Lichtquelle zum Aussenden eines optischen Signals mit zeitlich variierender Frequenz, insbesondere zur Verwendung in einer Vorrichtung zum Ermitteln eines Abstandes eines bewegten Objekts

Die Erfindung betrifft eine Lichtquelle zum Aussenden eines optischen Signals mit zeitlich variierender Frequenz, insbesondere zur Verwendung in einer Vorrichtung zum Ermitteln eines Abstandes eines bewegten Objekts, mit einem Laser (201, 251), einem ersten WGM-Resonator (210, 260), welcher an den Laser (201, 251) optisch gekoppelt ist, und einem zweiten WGM-Resonator (220, 270), welcher an den Laser (201, 251) optisch gekoppelt ist.

VERMESSUNG EINER KAVITÄT MITTELS INTERFERENZSPEKTROSKOPIE

Ein Verfahren zur interferometrischen Bestimmung der Parameter einer Kavität umfasst die Verfahrensschritte: – Durchstimmen der Frequenz f einer kohärenten Lichtquelle (10) über einen Frequenzbereich Δf, – Ableitung eines Zielstrahls und eines Referenzstrahls aus der kohärenten Lichtquelle (10), wobei der Zielstrahl wenigstens einmal die Kavität durchläuft, – Erzeugung eines von der Frequenz f der Lichtquelle abhängigen Interferenzsignals I(f) durch Überlagerung des Zielstrahls mit dem Referenzstrahl, und – Bestimmung der Amplitude und Phase des Interferenzsignals I(f) in Abhängigkeit von der Frequenz f der kohärenten Lichtquelle als Maß für die Länge x und/oder die optischen Parameter der Kavität (40, 45) durch Auswertung einer Vielzahl von Messpunkten des erfassten Interferenzsignals I(f) über den Frequenzbereich Δf und einem möglichen Vergleich mit verschiedenen Referenzmessungen, die die jeweils anderen (nicht zu messenden) Parameter der Kavität konstant halten.

Vorrichtung zum Betreiben eines kohärenten Lidar-Systems

Vorrichtung (100) zum Betreiben eines kohärenten Lidar-Systems (200), aufweisend:- eine Ermittlungseinrichtung (10) zum Ermitteln eines Überlagerungssignals zwischen einem Sendesignal (S) und wenigstens einem Reflexionssignal (R1...R4); und- eine Linearisierungseinrichtung (20) zum Bereitstellen eines Ansteuersignals für einen Laser (110) des Lidar-Systems (200) derart, dass das Sendesignal (S) eine lineare Frequenzänderung aufweist.

VERFAHREN UND VORRICHTUNG ZUR ABSTANDSMESSUNG DURCH LASERSTRAHLEN

LASERVORRICHTUNG, MESSVORRICHTUNG UND MESSVERFAHREN

Es werden eine Laservorrichtung 110, eine Messvorrichtung 100 und ein Messverfahren geschaffen, wobei die Laservorrichtung 110 einen frequenzmodulierten Laserstrahl mit mehreren Moden ausgibt und Folgendes enthält: einen optischen Hohlraum, der ein Verstärkungsmedium 114 zum Verstärken eines einzugebenden Lichts und einen optischen SSB-Modulator 30 zum Verschieben einer Frequenz des Lichts, das durch das Verstärkungsmedium verstärkt wurde, aufweist; und einen Steuerteil 50, der den optischen SSB-Modulator 30 steuert, um eine Frequenz von Licht, das in den optischen SSB-Modulator 30 eingegeben werden soll, zu verschieben.

High resolution remote imaging system providing depth information

EINRICHTUNG ZUR BERUEHRUNGSLOSEN GESCHWINDIGKEITS- UND/ODER ENTFERNUNGSMESSUNG

EINRICHTUNG ZUR BERUEHRUNGSLOSEN GESCHWINDIGKEITS- UND/ODER ENTFERNUNGSMESSUNG

Electro-optical method for measuring distance and detecting a non-ideal chirp profile

Laser radar system and method

Method and apparatus for reducing speckle noise in an optical system

The invention relates to a method and apparatus for reducing speckle noise in a system comprising a sensor for detecting electro-magnetic radiation backscattered from a target, comprising: illuminating the target with a first illuminating beam having a first optical path; illuminating the target with a second illuminating beam having a second optical path different to the first optical path; capturing at the sensor first and second backscattered radiation components associated with respectively the first and second illuminating beams, each of the backscattered radiation components comprising a speckle pattern; and taking a time-averaged measurement of the intensities of the first and second backscattered radiation components; wherein the capturing step is carried out within an integration time of the sensor, such that the time-averaged intensity measurement results in a decrease in speckle noise present in a signal representing the backscattered radiation.

LIDAR MEASURING DEVICE

The invention relates to a LIDAR measuring device and a method for determining the speed of particles in a measurement volume with a narrow-band continuous wave laser light source (1), which emits light which is coupled into a measuring branch (3) and a reference branch (4), wherein the light coupled into the measuring branch (3) is at least partially emitted by a transmitting device in the direction of the measuring volume in such a way that the emitted light is at least partially scattered and/or reflected by the particles in the measuring volume. A part of the scattered and/or reflected light is then received by a receiver device and is coherently superimposed with the light leaving the reference branch (4), and the resulting light beam is directed onto a detector (6) to generate a detector signal characteristic for the resulting light beam. Finally, the speed of the particles in the measuring volume is determined in an evaluation unit (11) by taking into account the detector signal.

NAVIGATION APPARATUS AND METHOD

Methods and apparatus for providing self-contained guidance, navigation, and control (GN&C) functions for a vehicle moving through an environment on or near the ground, in the air or in space without externally provided information are disclosed. The present invention provides enhanced navigation information about a universal reference frame (22) and one or more targets (20).

INCREASING RESOLUTION OF IMAGES OBTAINED FROM A THREE-DIMENSIONAL MEASUREMENT SYSTEM

A system uses range and Doppler velocity measurements from a lidar system and images from a video system to estimate a six degree-of-freedom trajectory (6DOF) of a target. The 6DOF transformation parameters are used to transform multiple images to the frame time of a selected image, thus obtaining multiple images at the same frame time. These multiple images may be used to increase a resolution of the image at each frame time, obtaining the collection of the superresolution images.

THREE DIMENSIONAL MEASUREMENT SYSTEM

A system for making distance measurements of remote points using a phenomenon related to the time of flight of an illuminating beam. A modulated beam of light is directed at the target area. The modulated beam has temporally varying information impressed upon it, such that the time of flight of the beam to the target and back can be related to the temporal signature of the received beam. An acousto-optic modulator is used to perform frequency conversion of the modulated light reflected from points in the field, before that light impinges on the pixels of a detector array. The AO modulation frequency is close to the illuminating light modulation frequency, so that the converted mixed frequency falls within the limited parallel reading rate range of the detector array, and contains the temporal signature information of the modulated light received from the target within signals of manageable frequencies.

Vorrichtung zur Bestimmung des Abstandes eines Gegenstandes von einem Bezugspunkt mittels einer von einem Sender ausgesandten Strahlung

Combined position and image evaluation sensor for remote object - has beam splitter within sensor stage coupled to ranging and viewing device

The sensor uses a planar mirror (2) with 2 degrees of movement in the measuring direction, supported by a horizontal rotatable sensor stage (1), exhibiting a beam splitter (32) lying along the vertical rotation axis (18). The beam splitter (32) allowing a target area of the viewed object to be focussed onto a photodetector (17) and a free surface (34) coupled with an electro-optical ranging and viewing device (7). USE/ADVANTAGE - For target tracking system. Allows simultaneous focussing of ranging and viewing light beams.

Optoelectronic distance measurement in construction and plant engineering industry, involves modulating optical intensities of main and reference emitters, and determining phase of resultant signals simultaneously

Optical intensities of main emitter (1) and reference emitter (2) are modulated simultaneously at different frequencies (f1,f2). The resultant frequencies are converted to intermediate frequency (IF) components (fzF1,fzF2). The separation of the phase information between the IF component is determined based on modulated difference frequencies (f1-f2) and IF difference frequencies (f(zF1)-f(zF2)). An independent claim is also included for optoelectronic distance measurement device.

Range finder/velocimeter and range-finding/velocimetry method

A laser driver (4) causes a semiconductor laser (1) to operate such that a first oscillation period of monotonically increasing the oscillation wavelength and a second oscillation period of monotonically decreasing the oscillation wavelength alternately exist. A photodiode (2) converts laser light emitted from the semiconductor laser (1) and return light from a measurement target (12) into electrical signals. A counting unit (13) counts the number of interference waveform components obtained from an output signal from the photodiode (2) in each of the first oscillation period and the second oscillation period. A computing device (9) calculates the distance to the measurement target (12) and the velocity of the measurement target (12) from a shortest Lasing wavelength and a longest Lasing wavelength in a period during which the counting unit (13) counts the number of interference waveform components and the counting result obtained by the counting unit (13). This makes it possible to measure ...

CONTROL OF PHASE IN STEERING OF LIDAR OUTPUT SIGNALS

The chip includes multiple steering waveguides positioned on a base. Each of the steering waveguides is being configured to carry an output signal. The steering waveguides each terminate at a facet. The facets are arranged such that output signals exit the chip through the facets and combine to form a LIDAR output signal. The chip also includes phase tuners positioned on at least a portion of the steering waveguides. Electronics operate the phase tuners so as to tune a phase differential between the output signals on adjacent steering waveguides. The electronics tune the phase differential so as to tune the direction that the LIDAR output signal travels away from the chip.

FMCW LIDAR METHODS AND APPARATUSES INCLUDING EXAMPLES HAVING FEEDBACK LOOPS

Methods and apparatuses are described for frequency-modulated continuous-wave (FMCW) light detection and ranging (LiDAR). Examples are provided where high-closed-loop bandwidth, active feedback applied to laser frequency chirps may provide increases in the free-running laser coherence length for long-range FMCW distance measurements. Examples are provided that use an asymmetric sideband generator within an active feedback loop for higher closed-loop bandwidth. Examples of using a single shared reference interferometer within multiple active feedback loops that may be used for increasing the coherence length of multiple chirped lasers are described. Example calibrators are also described.

Navigation system for GPS denied environments

Methods and apparatus for providing self-contained guidance, navigation, and control (GN&C) functions for a vehicle moving through an environment on or near the ground, in the air or in space without externally provided information are disclosed. More particularly, one embodiment of the present invention includes a Heading Sensor (36), an Absolute Location Sensor (38), a timer (40), a Range Doppler Processor (42), a Navigation Reference Sensor (44), an Area Range and a Velocity Sensor (46) which provide enhanced navigation information about a universal reference frame (22) and one or more targets (20).

DETECTOR DESIGNS FOR IMPROVED RESOLUTION IN LIDAR SYSTEMS

A lidar system includes a laser source, an emission lens configured to collimate and direct a laser beam emitted by the laser source, a receiving lens configured to receive and focus a return laser beam reflected off of one or more objects to a return beam spot at a focal plane of the receiving lens, and a detector including a plurality of photo sensors arranged as an array at the focal plane of the receiving lens. Each photo sensor has a respective sensing area and is configured to receive and detect a respective portion of the return laser beam. The lidar system further includes a processor configured to determine a respective time of flight for each respective portion of the return laser beam, and construct a three-dimensional image of the one or more objects based on the respective time of flight for each respective portion of the return laser beam.

SELECTIVE SUBBAND PROCESSING FOR A LIDAR SYSTEM

A signal processing system includes a time domain processing module to receive samples of a range-dependent time domain baseband signal in a frequency modulated continuous wave (FMCW) LIDAR system, and to generate and select time domain subband signals based on time domain subband selection criteria, a time domain to frequency domain converter coupled with the time domain processing module, to generate range-dependent frequency outputs from the selected time domain subbands, and a frequency domain processing module coupled with the time domain to frequency domain converter, to generate and select frequency domain subbands based on frequency domain subband collection criteria, and to detect energy peaks corresponding to target ranges in the field of view of the LIDAR system. 1. A frequency modulated continuous wave (FMCW) LIDAR system , comprising:a memory; and receive samples of a time domain baseband signal comprising range-dependent difference frequencies in the FMCW LIDAR system;', 'generate a plurality of frequency subbands in a time domain;', 'select a first set of subband signals from the plurality of frequency subbands, the first set of subband signals having energy values that exceed an energy threshold;', 'select a second set of subband signals from the first set of subband signals, the second set of subband signals having signal-to-noise ratio (SNR) values that exceed an SNR threshold;', 'convert the second set of subband signals in the time domain to a third set of subband signals in a frequency domain, wherein the third set of subband signals is resampled and combined; and', 'detect energy peaks and SNR peaks in the third set of subband signals to target ranges in a field of view of the FMCW LIDAR system., 'a processor, operatively coupled to the memory, to2. The FMCW LIDAR system of claim 1 , wherein the processor is further to:condition the samples of the range-dependent baseband signal;and resample and combine the set of selected subband signals into ...

POLARIZATION DIVERSITY DETECTION IN FMCW LIDAR

A system and method of classifying an object. The system includes a polarizing beam splitter, a first detector, a second detector and a processor. The polarizing beam splitter generates a first source signal having a first polarization direction and a second source signal having a second polarization. The first detector transmits the first source signal at the object and receives a first reflected signal generated at the object in response to the first source signal. The second detector transmits the second source signal at the object and receives a second reflected signal generated at the object in response to the second source signal. The processor is configured to compare the first reflected signal to the second reflected signal to classify the object.

Highly multiplexed coherent LIDAR system

A light detection and ranging (LIDAR) system comprises a laser diode; a laser diode driver circuit configured generate a laser beam using the laser diode and to frequency chirp the generated laser beam according to a frequency chirp period; a laser splitter to split the generated laser beam into N transmit laser beams pointed at different angles, wherein N is an integer greater than one, and a frequency chirp period of each of the N transmit laser beams is the frequency chirp period of the generated laser beam; and multiple return beam paths to receive N return beams and determine time of flight values for the N return beams in parallel.

MONITORING SIGNAL CHIRP IN LIDAR OUTPUT SIGNALS

Systems and methods for modular LADAR scanning

A laser distance and ranging (LADAR) array 300 comprises a plurality of LADAR modules 100 and a central processing device 302. Each LADAR module is configured to scan a laser beam 106 through a field of view (FOV) and output a signal indicating a distance between each LADAR module and any objects detected in the FOV of the laser beam. The central processing device is coupled to each of the LADAR modules and is configured to generate an output, such as an image, based at least in part on the signals of each LADAR module. The central processing device may comprise an analog-to-digital conversion unit and a fast Fourier transform unit. The modules can be arranged such that their respective FOVs are non-overlapping, partially overlapping or entirely overlapping or such that each LADAR module operates at a different phase.

Method and device for laser range-finding, for potentially fast-moving targets

FREQUENCY-MODULATED LASER-RADAR.

Electro-optical method for measuring distance and detecting a non-ideal chirp profile

OPTICAL SYSTEM INCLUDING HIGH PERFORMANCE OPTICAL RECEIVER AND METHOD THEREOF

Optical systems, devices, and methods are provided for determining various characteristics, such as quantity, movement, distance and speed/velocity of an object relative to the system. The system and method includes an optical transmitter to transmit an output optical signal carrying an electrical reference signal and an optical receiver to receive a reflection of the output optical signal. The receiver includes at least one local oscillator providing local oscillator light at a local oscillator frequency, at least one combiner to combine the reflection of the output optical signal with the local oscillator light into a coupled optical signal. An optical-electrical converter converts the coupled optical signal into a first electrical signal, which is rectified via an envelope detector/rectifier to provide a first rectified electrical signal, which is processed by a signal processor to calculate various characteristics of an object that reflected the output optical signal.

LIDAR SYSTEM BASED ON COMPLEMENTARY MODULATION OF MULTIPLE LASERS AND COHERENT RECEIVER FOR SIMULTANEOUS RANGE AND VELOCITY MEASUREMENT

A LIDAR system and method for determining a distance and a velocity of a target. The LIDAR system can include laser bank (62) is configured to generate a laser field from a first laser beam having a positive frequency sweep and a second laser beam having a negative frequency sweep, an optical combiner (65), an optical coupler (63), a photoreceiver (66), and a control circuit (69). The optical coupler direct a first portion of the laser field at the target such that the first portion is reflected by the target to the optical combiner. The optical combiner can optically combine the portions of the laser field. The output an l-output (67) and a Q-output (68) according to the optically combined portions of the laser field. The control circuit can determine a nominal beat frequency, which corresponds to the distance of the target, and a frequency shift, which corresponds to the velocity of the target, accordingly.

DETERMINATION OF AN ITEM OF DISTANCE INFORMATION FOR A VEHICLE

INTERFEROMETRIC DISTANCE-MEASURING METHOD WITH SPECTRALLY SEPARABLE DOUBLE CHIRP AND DEVICE

In a distance-measuring method, chirped laser radiation with two separable radiation components is emitted to at least one target to be surveyed and via a local oscillator path, the radiation components having an opposite chirp as a time dependency of the modulated wavelengths (.lambda.1, .lambda.2). After reception of the laser radiation scattered back from the target and passed via the local oscillator path, the laser radiation received is converted into signals and the distance to the at least one target is determined from the signals on the basis of interferometric mixing, separation of the radiation components being effected on the basis of their spectral characteristic.

INTERFEROMETRIC DISTANCE-MEASURING METHOD WITH DELAYED CHIRP SIGNAL AND SUCH AN APPARATUS

In a distance-measuring method comprising a distance- measuring apparatus having at least one frequency- modulatable laser source for producing chirped laser radiation. The laser radiation has radiation components with opposite chirp as time dependency of the modulated wavelengths, the simultaneous oppositeness of the frequency curve being realized via an optical delay path (3) for one of the two radiation components. The radiation produced is passed in a measuring interferometer (5) to a target (6) and parallel via a local Oscillator. After reception of the laser radiation scattered back from the target (6) and passed via the local oscillator path, the laser radiation received is converted into signals and the distance to the at least one target (6) is determined from the signals on the basis of interferometric mixing.

INTERFEROMETRIC DISTANCE-MEASURING METHOD WITH DELAYED CHIRP SIGNAL AND SUCH AN APPARATUS

In a distance-measuring method comprising a distance- measuring apparatus having at least one frequency- modulatable laser source for producing chirped laser radiation. The laser radiation has radiation components with opposite chirp as time dependency of the modulated wavelengths, the simultaneous oppositeness of the frequency curve being realized via an optical delay path (3) for one of the two radiation components. The radiation produced is passed in a measuring interferometer (5) to a target (6) and parallel via a local Oscillator. After reception of the laser radiation scattered back from the target (6) and passed via the local oscillator path, the laser radiation received is converted into signals and the distance to the at least one target (6) is determined from the signals on the basis of interferometric mixing.

INTERFEROMETRIC DISTANCE-MEASURING METHOD WITH SPECTRALLY SEPARABLE DOUBLE CHIRP AND SUCH AN APPARATUS

In a distance-measuring method, chirped laser radiation with two separable radiation components is emitted to at least one target to be surveyed and via a local oscillator path, the radiation components having an opposite chirp as a time dependency of the modulated wavelengths (?1, ?2). After reception of the laser radiation scattered back from the target and passed via the local oscillator path, the laser radiation received is converted into signals and the distance to the at least one target is determined from the signals on the basis of interferometric mixing, separation of the radiation components being effected on the basis of their spectral characteristic.

Pulse Compression Signal Processor Utilizing Identical Saw Matched Filters for Both Up and Down Chirps

TRANSMISSION DEVICE FOR EMITTING LIGHT

The invention relates to a transmission device for emitting light of at least one frequency. The transmission device is designed to emit light in different angular ranges such that the frequency of the light in each angular range is varied time-dependently in a respective frequency range, wherein frequencies in different frequency ranges for different angular ranges do not overlap at different points in time.

LIDAR WITH HETERODYNE DETECTION BY LOCAL OSCILLATOR AND DOUBLE PROBE BEAM, WITH ONE OR MORE SIMULTANEOUS FREQUENCIES, AND LIDAR DETECTION METHOD BY DOUBLE HETERODYNE DETECTION

System and method for solid state light detection and ranging (LIDAR) system, and solid state light detection and lasing (LIDAR) resolution enhancement

THREE DIMENSIONAL MEASUREMENT SYSTEM

A system for making distance measurements of remote points using a phenomenon related to the time of flight of an illuminating beam. A modulated beam of light is directed at the target area. The modulated beam has temporally varying information impressed upon it, such that the time of flight of the beam to the target and back can be related to the temporal signature of the received beam. An acousto-optic modulator is used to perform frequency conversion of the modulated light reflected from points in the field, before that light impinges on the pixels of a detector array. The AO modulation frequency is close to the illuminating light modulation frequency, so that the converted mixed frequency falls within the limited parallel reading rate range of the detector array, and contains the temporal signature information of the modulated light received from the target within signals of manageable frequencies.

Method for processing a signal from a coherent lidar in order to reduce noise and related lidar system

A method for processing a signal from a coherent lidar includes a coherent source, the method comprising steps consisting of: generating a first beat signal and a second beat signal, using respectively a first detection assembly and a second detection assembly for a plurality of n time intervals, determining n respective values of spectral density using a transform in the frequency domain of the cross-correlation between the first and second beat signals, determining a mean value of the spectral density using said n values of spectral density, determining a piece of location information on the target using the mean value of said spectral density.

Absolute object position location identification

In one general aspect, a non-transitory computer-readable storage medium can be configured to store instructions that when executed cause a processor to perform a process. The process can include transmitting a plurality of laser beams at a feature on an object, and calculating a candidate shape parameter representing the feature based on a plurality of laser beams reflected from the feature. The process can include determining that the candidate shape parameter matches a measured shape parameter stored in a shape parameter database and representing a measured feature of the object, and identifying an absolute location corresponding with the measured feature of the object.

VELOCITY ESTIMATION USING DOPPLER PER POINT LIDAR SYSTEMS

A method of operating a light detection and ranging (LiDAR) system is provided that includes performing a scene measurement using a LiDAR sensor capable of measuring Doppler per point. The method also includes estimating a velocity of the LiDAR sensor with respect to static points within the scene based on the scene measurement. The method may also include compensating for the velocity of the LiDAR sensor and compensating for a Doppler velocity of the LiDAR sensor.

Chirped coherent laser radar system and method

A laser radar system using collocated laser beams to unambiguously detects a range of a target and a range rate at which the target is moving relative to the laser radar system. Another aspect of various embodiments of the invention may relate to a laser radar system that uses multiple laser radar sections to obtain multiple simultaneous measurements (or substantially so), whereby both range and range rate can be determined without various temporal effects introduced by systems employing single laser sections taking sequential measurements. In addition, other aspects of various embodiments of the invention may enable faster determination of the range and rate of the target, a more accurate determination of the range and rate of the target, and/or may provide other advantages.

Chirped coherent laser radar system and method

A laser radar system using collocated laser beams to unambiguously detects a range of a target and a range rate at which the target is moving relative to the laser radar system. Another aspect of various embodiments of the invention may relate to a laser radar system that uses multiple laser radar sections to obtain multiple simultaneous measurements (or substantially so), whereby both range and range rate can be determined without various temporal effects introduced by systems employing single laser sections taking sequential measurements. In addition, other aspects of various embodiments of the invention may enable faster determination of the range and rate of the target, a more accurate determination of the range and rate of the target, and/or may provide other advantages.

CHARACTERIZING LINEARITY OF AN OPTICAL FREQUENCY CHIRP OUTPUT BY AN FMCW LASER

A system comprises an optical heterodyne device, the optical heterodyne device configured to generate an overlap signal based upon: 1) a first optical signal output by a frequency-modulated continuous-wave (FMCW) laser, wherein the first optical signal comprises an optical frequency chirp that is based upon an input voltage signal received by the FMCW laser; and 2) a second optical signal output by a reference laser. The system also includes a photodetector that is optically coupled to the optical heterodyne device, the photodetector configured to output an electrical beat signal based upon the mixing of the optical signals, wherein the electrical beat signal is representative of the mixed down optical signal. The system further includes a frequency analyzer system that generates, based upon the electrical beat signal, data that is indicative of linearity of the optical frequency chirp in the first optical signal.

Calibration and alignment of coherent lidar system

A lidar system includes a light source to generate a frequency modulated continuous wave (FMCW) signal, and a waveguide splitter to split the FMCW signal into an output signal and a local oscillator (LO) signal. A transmit coupler provides the output signal for transmission. A receive lens obtains a received signal resulting from reflection of the output signal by a target. A waveguide coupler combines the received signal and the LO signal into a first combined signal and a second combined signal. A first phase modulator and second phase modulator respectively adjust a phase of the first combined signal and the second combined signal to provide a first phase modulated signal and a second phase modulated signal to a first photodetector and a second photodetector. A processor processes a first electrical signal and a second electrical signal from the first and second photodetectors to obtain information about the target.

Phase-error correction in a synthetic aperture imaging system with local oscillator time delay adjustment

A method is for phase-error correction in a synthetic aperture (SA) imaging system. A transmission signal and a local oscillator (LO) signal are generated with a relative time delay, which can be adjusted in real-time to match a range to a target region to be imaged. A portion of the transmission signal is transmitted onto the target region and a return signal is collected and mixed with a portion of the LO signal to provide a raw SA signal. Transmission and LO phase errors associated respectively with the transmission and LO signals are determined, as well as a frequency jitter between the transmission and LO signals. A phase-corrected SA signal is obtained by applying a phase correction to the raw SA signal based on the transmission phase error, the LO phase error and the frequency jitter. An SA imaging system is capable of implementing the method for phase-error correction.

Signal Detection Apparatus, Method, and Applications

Apparatus and associated method for unambiguously evaluating high-bandwidth, rapidly changing analog range data in real time using low-cost components that allow detection of the signal of interest using a sampling rate that is lower than the Nyquist rate required to directly evaluate the full range data bandwidth.

Techniques to compensate for variations in phase over time in LIDAR systems

A method to compensate for phase impairments in a light detection and ranging (LIDAR) system includes transmitting a first optical beam towards a target, receiving a second optical beam from the target to produce a received optical beam; and generating a digitally-sampled target signal using a local oscillator (LO) beam, a first photo-detector and the received optical beam. The method also includes generating a digitally-sampled reference signal using a reference beam transmitted through a fiber delay device and a second photo-detector, and estimating one or more phase impairments in the LiDAR system using the digitally-sampled reference signal to produce one or more estimated phase impairments. The method also includes performing a first correction on a first phase impairment introduced into the digitally-sampled target signal by the LO beam; performing a second correction on a second phase impairment introduced into the digitally-sampled target signal by the received optical beam.

Integrated optical structures for LiDAR and other applications employing multiple detectors

Aspects of the present disclosure describe systems, methods, and structures—including LiDAR—that employ multiple detectors that may determine multiple incident angles of multiple received radiation beams and advantageously do not require or employ phase shifters in illustrative embodiments and may instead—employ optical Fourier transform structures.

Single beam digitally modulated lidar for autonomous vehicle distance sensing

According to one aspect, a relatively low-cost sensor for use on an autonomous vehicle is capable of detecting moving objects in a range or a zone that is between approximately 80 meters and approximately 300 meters away from the autonomous vehicle. A substantially single fan-shaped light beam is scanned for a full 360 degrees in azimuth. Using frequency-modulated-continuous-wave (FMCW) or phase coded modulation on the beam, with back end digital signal processing (DSP), moving objects may effectively be distinguished from a substantially stationary background.

Techniques for multiplexing optical beams in coherent LiDAR systems

A light detection and ranging (LiDAR) system that includes a first beam splitter to multiplex a first optical beam and a second optical beam into a combined beam having orthogonal linear polarizations. The system also includes lensing optics to emit the combined beam towards a target and collect light returned from the target in a return optical beam to be received by the first beam splitter. The first beam splitter demultiplexes the return optical beam into a first return beam and a second return beam having orthogonal linear polarizations. The system also includes an optical element to generate a first beat frequency from the first return beam and to generate a second beat frequency from the second return beam. The system also includes a signal processing system to determine a range and velocity of the target from the first beat frequency and the second beat frequency.

LIDAR MEASURING DEVICE

LIDAR BEAM WALK-OFF CORRECTION

Schaltung zur Signalaufbereitung von in einem Heterodyninterferometer auftretenden Signalen

The invention relates to circuitry for processing a reference signal (A) occurring in a heterodyne interferometer and a measuring signal (B). The basic frequency modulation signal of the heterodyne interferometer radiation source (19) leads to phase shifts in both signals (A,B).Signal filtering of both the reference signal (A) and the measuring signal (B) with a gate signal (C) cuts out signal segments from both signals (A,B) exhibiting the same phase sign. Further simplification of signal processing occurs through signal interpolation involving band pass filters (26,32) and by mixing the signals down to a lower frequency range within the heterodyne frequency (Fh). The input signals (L,N) provided by the inventive circuitry can be processed by a conventional phase indicator (37).

SAL (semi-active-laser) target-detection method

LASER RADAR SYSTEM AS WELL AS PROCEDURE FOR THE SUPPLY OF GECHIRPTER ELECTROMAGNETIC RADIATION

TIEFENMESSUNG WITH FREQUENCY-SHIFTED FEEDBACK LASER

Spatial profiling system and method

Abstract Described herein is a light detection and ranging method and system in which outgoing light is provided to a beam director wavelength based direction. A sequence of wavelength channels is directed in a first set of directions and another sequence wavelength channels is directed in a second set of directions, different to the first set of directions. In one example the system can scan an entire field of view and then revisit a portion of the field of view.

METHOD FOR PROCESSING A SIGNAL ARISING FROM COHERENT LIDAR AND ASSOCIATED LIDAR SYSTEM

L'invention concerne une méthode de traitement (50) d'un signal issu d'un lidar cohérent comprenant une source cohérente (L) modulée périodiquement en fréquence, - un signal de battement (Sb) étant généré par un photodétecteur (D) à partir de l'interférence entre un signal optique dénommé oscillateur local présentant une fréquence d'oscillateur local (fOL(t)) et un signal optique rétrodiffusé par une cible (T) illuminée par le lidar, ledit signal de battement étant numérisé, - la fréquence d'oscillateur local (fOL(t)) étant constituée de la somme d'une valeur moyenne (f0) et d'une fréquence de modulation (fmod(t)) issue de la modulation de la source, la fréquence de modulation étant périodique selon une période de modulation (TFO), chaque période comprenant n parties linéaires présentant respectivement n pentes de fréquence (ai), n étant supérieur ou égal à 2, la méthode comprenant les étapes consistant à : - moduler (501 ) de manière complexe le signal de battement (Sb), - démoduler (502 ...

SWITCHABLE COHERENT PIXEL ARRAY FOR FREQUENCY MODULATED CONTINUOUS WAVE LIGHT DETECTION AND RANGING

A FMCW LiDAR transceiver includes an input port, optical antennas, an optical switch, splitters, and mixers. The optical switch switchably couples an input port to the optical antennas, thereby forming optical paths between the input port and the optical antennas. For each optical path from the input port to one of the optical antennas, a splitter is coupled along the optical path. The splitter splits a received portion of a laser signal into a local oscillator signal and a transmitted signal and outputs a return signal that is a portion of the reflected signal. The transmitted signal is emitted via the optical antenna and a reflection of the transmitted signal is received via the optical antenna as a reflected signal. For each splitter, a mixer receives the return signal and the local oscillator signal and mixes the return signal and the local oscillator signal to generate output signals.

SIGNAL-PROCESSING DEVICE, PROCESSING METHOD, RECORDING MEDIUM, TARGET DETECTION DEVICE, AND DETECTION METHOD

The purpose of the present invention is to reduce the effects of scattering from a medium, during continuous transmission of waves and detection of a target. The invention is provided with: a transmitter for continuous transmission of waves for propagation through a medium; a receiver for receiving reflected waves produced when the waves are reflected within the medium; a signal-processing device for estimating a lower limit distance of a detection distance range in which the intensity level of scattered waves from the medium in the detection distance range is at or below a permissible level, and outputting a signal obtained by eliminating from the reflected wave signal received by the receiver a scattered wave signal from the medium in a masking area from the receiver to the lower limit distance; and a detector for detecting a target within the medium, on the basis of the output from the signal-processing device.

Method and device for operating a plurality of sensors of a vehicle

Method for processing a signal arising from coherent lidar and associated lidar system

A method for processing a signal arising from coherent lidar includes a coherent source that is periodically frequency-modulated; a beat signal being generated by photodetector on the basis of the interference between an optical signal that is referred to as the local oscillator having a local oscillator frequency (fOL(t)) and an optical signal that is backscattered by a target illuminated by the lidar, said beat signal being digitized; the local oscillator frequency (fOL(t)) being made up of the sum of a mean value (f0) and of a modulation frequency (fmod(t)) arising from the modulation of the source, the modulation frequency being periodic according to a modulation period (TFO), each period comprising n linear portions having n frequency slopes (αi), respectively, where n is greater than or equal to 2, the method comprising the steps consisting in: complexly modulating the beat signal; complexly demodulating the modulated signal (Smod) by n demodulation frequencies (fdemod(i)) each having ...

SYSTEMS AND METHODS FOR MEASURING CHARACTERISTICS OF AN OBJECT AT DISTANCE

Systems and methods for detection of distances, velocities, and characteristics of a surface measured by a lidar sensor are described herein.

Adjustable pulse characteristics for ground detection in lidar systems

A method in a lidar system for scanning a field of regard of the lidar system is provided. The method includes identifying, within the field of regard, a ground portion that overlaps a region of ground located ahead of the lidar system; causing a light source to emit pulses of light; scanning at least a portion of the emitted pulses of light along a scan pattern contained within the field of regard, including adjusting a scan parameter so that at least one of a resolution or a pulse energy for the ground portion of the field of regard is modified relative to another portion of the field of regard; and detecting at least a portion of the scanned pulses of light scattered by one or more remote targets.

METHOD AND SYSTEM FOR SIDELOBE SUPPRESSION IN PHASE ENCODED DOPPLER LIDAR

A light detection and ranging (LIDAR) system includes one or more processors, and one or more computer-readable storage mediums storing instructions which, when executed by the one or more processors, cause the one or more processors to determine a code that has a first number of symbols, transmit, to an environment, an optical signal generated based on the code such that the first number of symbols are transmitted in a first duration, in response to transmitting the optical signal, receive a returned optical signal that is reflected from an object in the environment, sample, from the returned optical signal, a second number of symbols in a second duration, the second number being different from the first number, and determine, based on the second number of symbols, a range to the object. 1. A light detection and ranging (LIDAR) system , the LIDAR system comprising: determine a code that has a first number of symbols;', 'transmit, to an environment, an optical signal generated based on the code such that the first number of symbols are transmitted in a first duration;', 'in response to transmitting the optical signal, receive a returned optical signal that is reflected from an object in the environment;', 'sample, from the returned optical signal, a second number of symbols in a second duration, the second number being different from the first number; and', 'determine, based on the second number of symbols, a range to the object., 'one or more processors; and one or more computer-readable storage mediums storing instructions which, when executed by the one or more processors, cause the one or more processors to2. The LIDAR system as recited in claim 1 , wherein the second duration has the same length as the first duration.3. The LIDAR system as recited in claim 1 , wherein the second number of symbols are sampled based on a first clock signal claim 1 , the first number of symbols are transmitted based on a second clock signal claim 1 , and the one or more processors ...

Techniques for mitigating lag-angle effects for LIDARs scans

A LIDAR system includes an optical source and multiple waveguides at different positions within the LIDAR system to receive a return signal. A first waveguide receives a first portion of the return signal at a first angle relative to the scanning mirror and a second waveguide receives a second portion of the return signal at a second angle relative to the scanning mirror. The system further includes multiple optical detectors at different positions within the LIDAR system. A first optical detector receives the first portion of the return signal from the first waveguide and a second optical detector receives the second portion of the return signal from the second waveguide. The system further includes a signal processing system operatively coupled to the plurality of optical detectors to determine a distance and velocity of the target object based on the returned signal and corresponding positions of the plurality of waveguides.

PHYSICAL QUANTITY SENSOR AND PHYSICAL QUANTITY MEASURING UNIT

A physical quantity sensor includes a semiconductor laser for irradiating an object with a laser beam, and a laser driver for operating the semiconductor laser in such a way that a first oscillation period for which the oscillation wavelength increases and/or a second oscillation period for which the oscillation wavelength decreases is repetitively present. The sensor further includes a photodiode and a current-voltage conversion amplifying unit both for detecting an MHP containing an interference waveform formed by the self-coupling effect between the laser beam and the returning light beam from the object, a MHP extracting unit for measuring the period of the interference waveform contained in the output signal from the current-voltage conversion amplifying unit each time the interference waveform is inputted, and a computing unit for computing the displacement and/or the speed of the object from the measured individual period MHP extracting unit.

LIDAR SYSTEM WITH PULSED AND FREQUENCY-MODULATED LIGHT

DEVICE FOR SCANNING FMCW LIDAR RANGE MEASUREMENT

A device (14) for scanning FMCW LiDAR range measurement comprises a light source (16) producing light having a varying frequency, a splitter (22) splitting the light into reference light and output light, and an optical system (31) having an optical axis (OA). A plurality of free space couplers (29) are arranged along a line (47) such that the distance (d) between adjacent free space couplers (29) increases with increasing distance from the optical axis (OA). Each free space coupler outcouples the output light into the free space and receives input light that was reflected at an object (12). A detector (32) detects a superposition of the input light with the reference light, and a calculation unit (34) determines the range to the object (12) from the superposition detected by the detector (32).

DEVICE FOR SUPPRESSING VERY CLOSE INTERFERENCE ECHO SIGNALS IN OPTICAL PULSE COMPRESSION RADARS

Dual laser frequency sweep interferometry system and method

PROCESSING METHOD FOR A COMPOSITE SIGNAL

Spatial profiling system and method

Abstract Described herein is a spatial processing system including a first unit and a second unit that is different to and remote from the first unit. The first unit includes a light source, a light receiver and a processing unit. The second unit includes a beam director. The spatial processing system also includes optical coupling between the first unit and the second unit. The first unit is configured to operate the light source to provide outgoing light to the optical coupling. The outgoing light comprises light at a plurality of different wavelength channels. The second unit is configured to receive the outgoing light and spatially direct, by at least one passive dispersive component of the beam director, the outgoing light into an environment, wherein the spatial direction of the light into the environment is based on wavelength. The second unit is also configured to receive at least part of the outgoing light reflected by the environment and provide the reflected light to the optical ...

Optical system including high performance optical receiver and method thereof

Optical systems, devices, and methods are provided for determining various characteristics, such as quantity, movement, distance and speed/velocity of an object relative to the system. The system and method includes an optical transmitter to transmit an output optical signal carrying an electrical reference signal and an optical receiver to receive a reflection of the output optical signal. The receiver includes at least one local oscillator providing local oscillator light at a local oscillator frequency, at least one combiner to combine the reflection of the output optical signal with the local oscillator light into a coupled optical signal. An optical-electrical converter converts the coupled optical signal into a first electrical signal, which is rectified via an envelope detector/rectifier to provide a first rectified electrical signal, which is processed by a signal processor to calculate various characteristics of an object that reflected the output optical signal.

System and method for generating three dimensional images using lidar and video measurements

A system uses range and Doppler velocity measurements from a lidar system and images from a video system to estimate a six degree-of-freedom trajectory of a target. The system estimates this trajectory in two stages: a first stage in which the range and Doppler measurements from the lidar system along with various feature measurements obtained from the images from the video system are used to estimate first stage motion aspects of the target (i.e., the trajectory of the target); and a second stage in which the images from the video system and the first stage motion aspects of the target are used to estimate second stage motion aspects of the target. Once the second stage motion aspects of the target are estimated, a three-dimensional image of the target may be generated.

System and method for generating three dimensional images using lidar and video measurements

A system uses range and Doppler velocity measurements from a lidar system and images from a video system to estimate a six degree-of-freedom trajectory of a target. The system estimates this trajectory in two stages: a first stage in which the range and Doppler measurements from the lidar system along with various feature measurements obtained from the images from the video system are used to estimate first stage motion aspects of the target (i.e., the trajectory of the target); and a second stage in which the images from the video system and the first stage motion aspects of the target are used to estimate second stage motion aspects of the target. Once the second stage motion aspects of the target are estimated, a three-dimensional image of the target may be generated.

METHOD FOR MEASURING THE FREQUENCY MODULATION OF A LASER SOURCE

The invention concerns a method for measuring the frequency modulation f(t) of a laser source, that comprises the following steps: - modulating the laser source over a period T, by means of a modulation control, - during a same period T, carrying out several measurements of a light beat intensity between two arms of an interferometer located downstream from the laser source and capable of introducing a delay t between the two arms, said measurements being synchronised with the modulation control, - calculating the frequency f(t) from the measurements, - during each period T, f(t) varies but delay t is considered to be constant, - delay t changes temporally over several periods T, - the measurements taken at time ti during a same period are repeated at ti+k T, with k=1, and delay t has changed from one iteration to another.

DETERMINATION OF AN ITEM OF DISTANCE INFORMATION FOR A VEHICLE

The present invention relates to a method and a device for determining an item of distance information for a vehicle. In the method, a light source (11) of the vehicle (10) is actuated using a modulated signal and light (16), which was emitted by the light source (11) and was reflected from an object (17) in an environment of the vehicle (10), is received. A reception signal is generated as a function of the received light (16) and a correlation signal is generated by correlating the modulated signal with the reception signal. A distance (18) to the object (17) is determined as a function of the correlation signal.

SYSTEM FOR OPTICALLY CHARACTERIZING AN AREA OF INTEREST OF AN OBJECT

Multiple resolution based 3 - D LIDAR measurements Simultaneous localization and mapping

Varying Waveforms Across Frames in Frequency-Modulated Continuous-Wave (FMCW) Lidar Systems

This document describes techniques and systems to vary waveforms across frames in lidar systems. The described lidar system transmits signals with different waveforms for the same pixel of consecutive frames to avoid a return signal overlapping with a noise spike or a frequency component of another return signal. The different waveforms can be formed using different frequency modulations, different amplitude modulations, or a combination thereof for the same pixel of consecutive frames. The lidar system can change the waveform of the transmit signal for the same pixel of a subsequent frame automatically or in response to determining that a signal-to-noise ratio of the return signal of an initial frame is below a threshold value. In this way, the lidar system can increase the signal-to-noise ratios in return signals. These improvements allow the lidar system to increase its accuracy in determining the characteristics of objects that reflected the return signals.

System and method for measuring velocity using frequency modulation of laser output

The invention relates to a system for measuring velocity. In one embodiment, the system includes a laser assembly having a laser diode and a power detection diode. The laser diode emits a plurality of laser signals which are frequency-modulated, wherein a selected one of the frequency-modulated signals is directed to and reflected from a target, and wherein another selected one of the frequency-modulated laser signals transmitted via one signal path is combined with the reflected laser signal transmitted via another delayed signal path in the interior of the laser assembly. The power detection diode detects the combined signal. The system also includes a signal processor configured to obtain velocity information from the detected signal by use of the harmonic frequencies associated with the modulation frequency.

Time Shifted PN Codes for CW LIDAR, RADAR, and SONAR

A continuous wave Light Detection and Ranging (CW LiDAR) system utilizes two or more laser frequencies and time or range shifted pseudorandom noise (PN) codes to discriminate between the laser frequencies. The performance of these codes can be improved by subtracting out the bias before processing. The CW LiDAR system may be mounted to an artificial satellite orbiting the earth, and the relative strength of the return signal for each frequency can be utilized to determine the concentration of selected gases or other substances in the atmosphere.

DOPPLER TIME-OF-FLIGHT IMAGING

Systems and methods for imaging object velocity are provided. In an embodiment, at least one Time-of-Flight camera is used to capture a signal representative of an object in motion over an exposure time. Illumination and modulation frequency of the captured motion are coded within the exposure time. A change of illumination frequency is mapped to measured pixel intensities of the captured motion within the exposure time, and information about a Doppler shift in the illumination frequency is extracted to obtain a measurement of instantaneous per pixel velocity of the object in motion. The radial velocity information of the object in motion can be simultaneously captured for each pixel captured within the exposure time. In one or more aspects, the illumination frequency can be coded orthogonal to the modulation frequency of the captured motion. The change of illumination frequency can correspond to radial object velocity.

Laser tracker

Some embodiments of the invention include a coordinate measuring machine for detecting the position and alignment of a spatially movable measuring aid. The coordinate measuring machine may include a retroreflector; a base; a support, which is fixed on the base rotatably about a first rotation axis; a beam directing unit, which is fixed to the support rotatably about a second rotation axis substantially orthogonal to the first rotation axis; means for detecting a rotation angle of the support relative to the base; and means for detecting a rotation angle of the beam directing unit relative to the support. In some embodiments, the beam directing unit comprises a laser emission and reception optical unit and a first optical distance measuring unit having at least one first distance measuring device for measuring the distance to a retroreflector of the measuring aid by means of a first measurement radiation.

Self-mixing interference device for sensing applications

Disclosed herein are self-mixing interferometry (SMI) sensors, such as may include vertical cavity surface emitting laser (VCSEL) diodes and resonance cavity photodetectors (RCPDs). Structures for the VCSEL diodes and RCPDs are disclosed. In some embodiments, a VCSEL diode and an RCPD are laterally adjacent and formed from a common set of semiconductor layers epitaxially formed on a common substrate. In some embodiments, a first and a second VCSEL diode are laterally adjacent and formed from a common set of semiconductor layers epitaxially formed on a common substrate, and an RCPD is formed on the second VCSEL diode. In some embodiments, a VCSEL diode may include two quantum well layers, with a tunnel junction layer between them. In some embodiments, an RCPD may be vertically integrated with a VCSEL diode.

LIDAR system with a multi-mode waveguide photodetector

A light detection and ranging (LIDAR) apparatus is provided that includes an optical source configured to emit an optical beam. The LIDAR apparatus further includes free space optics configured to receive a first portion of the optical beam as a target signal and a second portion of the optical beam as a local oscillator signal, and combine the target signal and the local oscillator signal. The LIDAR apparatus includes a multi-mode (MM) waveguide configured to receive the combined signal.

SYSTEM FOR EMULATING AN ENVIRONMENT FOR TESTING A FREQUENCY MODULATED CONTINUOUS WAVE (FMCW) LIGHT DETECTION AND RANGING (L1DAR) SYSTEM

METHOD AND DEVICE FOR DETERMINING, BY SCANNING, THE DISTANCE AND SPEED OF AT LEAST ONE OBJECT

COHERENT LIDAR IMAGING METHOD AND ASSOCIATED LIDAR

Tiefenmessung mit frequenzverschobenem Rückkopplungslaser

METHOD AND APPARATUS FOR MEASURING DISTANCE BY LASER BEAM

Spatial profiling system and method

Abstract Described herein is a spatial profiling system including a light source, a beam director, a light receiver and a processing unit. The light source is configured to provide outgoing light at a plurality of wavelength channels, including first outgoing light having at least one time varying attribute at a first wavelength channel and to provide second outgoing light having at least one time varying attribute at a second wavelength channel, different to the first wavelength channel. The beam director is configured to spatially direct the outgoing light into an environment having a spatial profile, wherein the spatial direction is based on wavelength and includes directing the first outgoing light in a first direction and directing the second outgoing light in a second direction, different to the first direction. The light receiver is configured to receive at least part of the first outgoing light reflected by the environment and to receive at least part of the second outgoing light ...

Velocity measuring device and method

A velocity measuring device emitting a laser beam at a web; a photodiode converting an optical output of the laser into an electric signal; a laser driver operating the laser to alternate a first emitting interval wherein the oscillating wavelength increases and a second emitting interval wherein the oscillating wavelength decreases; a current-voltage converting/amplifying portion converting the electric current from the photodiode into a voltage; a filter portion removing a carrier wave from the output of the current-voltage converting/amplifying portion; a signal extracting portion calculating a number of interference waveforms in the output of the filter portion; and a calculator calculating the velocity of the web based on the result of the extracting portion. The laser driver operates so the absolute values for the rates of change, in respect to time, of the oscillating wavelengths during the first emitting interval and during the second emitting interval are different.

Switchable coherent pixel array for frequency modulated continuous wave light detection and ranging

A LIDAR transceiver includes an input port, optical antennas, an optical switch, splitters, and mixers. The optical switch switchably couples an input port to the optical antennas. For at least one optical path from the input port to one of the optical antennas, a splitter is coupled along the optical path. The splitter splits a received portion of a laser signal into a local oscillator signal and a transmit signal and outputs a return signal that is a portion of the reflected signal. The transmit signal is emitted through the optical antenna and a reflection of the transmit signal is received through the optical antenna as a reflected signal.

LASER RADAR DEVICE

In a conventional laser radar device, there has been a problem that since a distance resolution is changed in advance depending on a measurement distance, it is necessary to perform measurement again after changing the distance resolution. A laser radar device of the present invention includes: an optical oscillator oscillating laser light; an optical modulator modulating the laser light oscillated by the optical oscillator; an optical antenna radiating the laser light modulated by the optical modulator to an atmosphere, and receiving scattered light from a radiation target as received light; an optical receiver performing heterodyne detection on the received light received by the optical antenna; and a signal processor calculating for a range bin a spectrum of a received signal obtained by the heterodyne detection by the optical receiver, calculating a signal to noise ratio of the range bin, and integrating the spectrum of the range bin and spectra of one or more range bins adjacent to the range bin when the signal to noise ratio is less than or equal to a threshold value. 1an optical oscillator oscillating laser light;an optical modulator modulating the laser light oscillated by the optical oscillator;an optical antenna radiating the laser light modulated by the optical modulator to an atmosphere, and receiving scattered light from a radiation target as received light;an optical receiver performing heterodyne detection on the received light received by the optical antenna; anda signal processor calculating for a range bin a spectrum of a received signal obtained by the heterodyne detection by the optical receiver, calculating a signal to noise ratio of the range bin, and integrating the spectrum of the range bin and spectra of one or more range bins adjacent to the range bin when the signal to noise ratio is less than or equal to a threshold value, wherein the signal processor includes:a range bin divider dividing the received signal into range bins each having a ...

Dual-laser chip-scale lidar for simultaneous range-doppler sensing

A chip-scale lidar system includes a first light source to output a first signal, and a second light source to output a second signal. A transmit beam coupler provides an output signal for transmission that includes a portion of the first signal and a portion of the second signal, and receive beam coupler obtains a received signal resulting from reflection of the output signal by a target. The system includes a first and second set of photodetectors to obtain a first and second set of electrical currents from a first and second set of combined signals including a first and second portion of the received signal. A processor obtains Doppler information about the target from the second set of electrical currents and obtains range information about the target from the first set of electrical currents and the second set of electrical currents.

METHOD AND SYSTEM FOR SIDELOBE SUPPRESSION IN PHASE ENCODED DOPPLER LIDAR

A system and method for sidelobe suppression in phase-encoded Doppler LIDAR to support the operation of a vehicle includes determining a sequence code that is indicative of a sequence of phases for an optical signal; modulating an optical signal based on the sequence code to produce a phase-encoded optical signal; transmitting the phase-encoded optical signal to an environment; receiving, from the environment, a returned optical signal in response to transmitting the phase-encoded optical signal; generating, based on the returned optical signal, an electrical signal; and determine a Doppler frequency shift in the returned optical signal. 1. A light detection and ranging (LIDAR) system , the LIDAR system comprising: determine an m-sequence code that is indicative of a sequence of phases for an optical signal;', 'modulate an optical signal based on the m-sequence code to produce a phase-encoded optical signal;', 'transmit the phase-encoded optical signal to an environment;', 'receive, from the environment, a returned optical signal in response to transmitting the phase-encoded optical signal;', 'generate, based on the returned optical signal, an electrical signal; and', 'determine a Doppler frequency shift in the returned optical signal based on the electrical signal., 'one or more processors; and one or more computer-readable storage mediums storing instructions which, when executed by the one or more processors, cause the one or more processors to2. The LIDAR system as recited in claim 1 , wherein the one or more processors are further configured to:step up or stepping down a clock signal relative to a clock signal for generating the electrical signal.3. The LIDAR system as recited in claim 1 , wherein the m-sequence code has symbols of a first length and the electrical signal has samples of a second length claim 1 , and wherein the one or more processors are further configured to:sample the m-sequence code to generate a sampled signal; andinterpolate the sampled ...

DISTANCE MEASUREMENT DEVICE AND CONTROL METHOD

A distance measurement device () generates transmission light by modulating an optical carrier wave. The distance measurement device () transmits the generated transmission light, and receives reflected light acquired by the transmission light being reflected by a measured object (). The distance measurement device () generates a first beat signal by causing the transmission light to interfere with reference light. The distance measurement device () generates a second beat signal by causing the reflected light to interfere with the reference light. The distance measurement device () calculates a distance to the measured object (), based on a difference between the first beat signal and the second beat signal. 1. A distance measurement device , comprising:modulation means for generating transmission light by modulating an optical carrier wave;transmission means for transmitting the generated transmission light;reception means for receiving reflected light being light acquired by the transmission light being reflected by a measured object;first beat signal generation means for generating a first beat signal by causing the transmission light to interfere with reference light;second beat signal generation means for generating a second beat signal by causing the reflected light to interfere with the reference light; andcalculation means for calculating a distance to the measured object, based on a difference between the first beat signal and the second beat signal.2. The distance measurement device according to claim 1 , whereinthe modulation means generates transmission light by shifting a frequency of the optical carrier wave, andthe calculation means specifies a phase difference between the transmission light and the reflected light from a difference between the first beat signal and the second beat signal, and calculates a distance to the measured object, based on the specified phase difference.3. The distance measurement device according to claim 1 , whereinthe ...

PRECISELY CONTROLLED CHIRPED DIODE LASER AND COHERENT LIDAR SYSTEM

A light detection and ranging (LIDAR) system may include a laser source configured to emit one or more optical beams; a scanning optical system configured to scan the one or more optical beams over a scene and capture reflections of the one or more optical beams from the scene; a measurement system configured to divide the scene into a plurality of pixels, the measurement system comprising a detector configured to detect a return signal from multiple pixels of the plurality of pixels as the one or more optical beams are scanned across the scene, and a data processor configured to perform data processing from the return signal from the multiple pixels to determine a range and/or range rate for each pixel of the scene. 1. A light detection and ranging (LIDAR) system , comprising:a laser source configured to emit one or more optical beams;a scanning optical system configured to scan the one or more optical beams over a scene and capture reflections of the one or more optical beams from the scene,a measurement system configured to divide the scene into a plurality of pixels, the measurement system comprising a detector configured to detect a return signal from multiple pixels of the plurality of pixels as the one or more optical beams are scanned across the scene, anda data processor configured to perform data processing from the return signal from the multiple pixels to determine a range and/or range rate for each pixel of the scene.2. The LIDAR system of claim 1 ,the laser source configured to vary the optical frequency of the one or more optical beams in accordance with a periodic frequency versus time function.3. The LIDAR system of claim 1 ,wherein the data processing comprises a sliding-window data processing from the return signal from the multiple pixels to determine the range and/or range rate for each pixel of the scene.4. The LIDAR system of claim 3 ,wherein the sliding-window data processing comprises a sliding-window Fourier transformation.5. A light ...

Semiconductor optical amplifier with bragg grating

In one embodiment, a light source is configured to emit an optical signal. The light source includes a seed laser diode configured to produce a seed optical signal and a semiconductor optical amplifier (SOA) configured to amplify the seed optical signal to produce the emitted optical signal. The SOA includes an optical waveguide extending along a longitudinal direction from an input end of the SOA to an output end of the SOA. The optical waveguide is configured to guide and provide optical gain to the seed optical signal while the seed optical signal propagates in the longitudinal direction along the optical waveguide from the input end to the output end. The SOA also includes a Bragg grating disposed parallel to the optical waveguide, where the Bragg grating includes a region of the SOA having a refractive index that varies along the longitudinal direction.

APPARATUS AND METHOD FOR ASCERTAINING A DISTANCE TO AN OBJECT

An apparatus for ascertaining a distance to an object has a light source unit for emitting an optical signal with a time-varying frequency, an evaluation device for ascertaining a distance to the object based on (a) a measurement signal that arose from the signal and was reflected at the object and (b) a reference signal that was not reflected at the object. The apparatus has also a dispersive element disposed in the signal path of the optical signal and an optical position sensor disposed downstream of this dispersive element in the signal path. 1. An apparatus for ascertaining a distance to an object , wherein the apparatus comprises:a light source unit configured to emit an optical signal having a time-varying frequency, a measurement signal that originated from the signal and was reflected at the object and', 'a reference signal that was not reflected at the object,, 'an evaluation device configured to ascertain a distance to the object based onat least one dispersive element disposed in a signal path of the optical signal,at least one optical position sensor disposed downstream of the dispersive element in the signal path, anda monitoring unit configured to monitor a luminous power emitted by the light source unit based on sensor signals supplied by the optical position sensor.2. The apparatus of claim 1 , wherein the dispersive element forms a scanning device configured to deflect claim 1 , in a frequency-dependent manner claim 1 , measurement beams claim 1 , which originated from the optical signal claim 1 , into different beam directions towards the object.3. The apparatus of claim 2 , wherein the apparatus is configured to ascertain beam directions of the measurement beams based on sensor signals supplied by the optical position sensor.4. The apparatus according to claim 2 , wherein the scanning device is configured to deflect the measurement beams in a frequency-dependent manner into two mutually perpendicular directions.5. The apparatus of claim 1 , ...

APPARATUS FOR ASCERTAINING A DISTANCE TO AN OBJECT

An apparatus for ascertaining a distance to an object has a light source that emits an optical signal having a time-varying frequency. An evaluation device ascertains a distance to the object based on a measurement signal that originated from the optical signal and was reflected at the object and, and on a reference signal that was not reflected at the object. A deflection device changes an angle, at which the measurement signal is steered to the object, during a period of the optical signal in which the frequency of the optical signal has a monotonic time dependence. 1. An apparatus for ascertainment of a distance to an object , wherein the apparatus comprisesa light source configured to emit an optical signal having a time-varying frequency, a measurement signal that originated from the optical signal and was reflected at the object and', 'a reference signal that was not reflected at the object, and, 'an evaluation device configured to ascertain a distance to the object based on'}a deflection device configured to change an angle, at which the measurement signal is steered to the object, during a period of the optical signal in which the frequency of the optical signal has a monotonic time dependence.2. The apparatus of claim 1 , comprising an element configured to produce a frequency-selective spatial division of the measurement signal reflected at the object.3. The apparatus of claim 2 , wherein the element comprises an array waveguide grating (AWS).4. The apparatus of claim 2 , wherein the element comprises a prism claim 2 , a diffraction grating or a spatial light modulator.5. The apparatus of claim 4 , wherein the spatial light modulator is an acoustic modulator or an electro-optic modulator.6. The apparatus of claim 2 , comprising a coupler array that has a plurality of mutually independently operable coupling elements for separate merging of partial signals claim 2 , which were generated by the frequency-selective spatial division of the measurement signal ...

Apparatus for ascertaining a distance to an object

An apparatus for ascertaining a distance to an object has a light source that emits an optical signal having a time-varying frequency. An evaluation device ascertains a distance to the object based on a measurement signal that originated from the optical signal and was reflected at the object and, and on a reference signal that was not reflected at the object. A dispersive element produces a frequency-selective angle distribution of the measurement signal that has a plurality of partial signals which are steered to the object at mutually different angles.

Method and apparatus for coherence enhancement of sweep velocity locked lasers via all-electronic upconversion

The present disclosure provides methods and apparatus to improve the dynamic coherent length of a sweep velocity-locked laser pulse generator (SV-LLPG) in an all-electronic fashion. A digital SV-LLPG is disclosed with two operation modes, i.e., unidirectional and bidirectional sweep modes; self-adaptive and time-dependent loop parameters (gain and location of poles/zeros); and, self-adaptive initial input curve. High frequency locking architectures, both single-side band (SSB) modulation method and direct phase measurement method, are provided to suppress the linewidth, or improve the coherent length, of the swept laser. A combination of high and low frequency locking, or a combination of multiple architectures disclosed in this invention, is utilized to achieve a higher level of linewidth reduction. The enhanced laser coherence extends the measurement range by at least one order of magnitude for applications including frequency-modulated continuous wave (FMCW) light detection and ranging (LiDAR) and optical fiber distributed sensing applications.

FMCW IMAGING LIDAR BASED ON COHERENT PIXEL ARRAY

A frequency-modulated continuous wave (FMCW) imaging light detection and ranging (LiDAR) system includes an integrated photonic circuit based coherent pixel array sensor having a large number of coherent pixels. Each pixel receives both the frequency-modulated signal light from a local light source (LO) and the returned signal light reflected from a section of the target scene through an imaging optical system. At each pixel, the LO light and the returned light are mixed locally by an optical mixer and then detected locally by an integrated photodetector. The electrical signal from each pixel is used to calculate scene distance using FMCW LiDAR principles. The LO signal is distributed into each pixel by an on-chip optical switch and routing circuit. An optical phased array may be used to split the source beam into the LO light and the target illumination light and to steer the illumination light. 1. A frequency-modulated continuous wave (FMCW) imaging light detection and ranging (LiDAR) system , comprising:a laser source configured to emit a frequency-modulated, continuous wave optical beam;a beam splitting device configured to split the optical beam emitted by the laser source, to form an illumination optical beam using a first portion of the optical beam and to direct the illumination optical beam into free space to illuminate a target scene;a coherent pixel array sensor, including a spatial array of coherent pixels and an optical distribution circuit;an imaging optical system, configured to image the target scene onto the array of coherent pixels;wherein the beam splitting device is further configured to guide a second portion of the optical beam emitted by the laser source into the optical distribution circuit of the coherent pixel array sensor as a local oscillator signal;wherein the optical distribution circuit is configured to feed a portion of the local oscillator signal to each of the coherent pixels;wherein each coherent pixel is configured to receive a ...

Modulated Laser Range Finder and Method

A laser range finder including a laser configured to project a laser beam onto a target object thereby causing a target beam to be reflected from the target object, wherein the laser beam has a frequency, and wherein the frequency is modulated at a known rate, a first beam splitter positioned to split a reference beam from the laser beam, a second beam splitter positioned to receive the target beam and the reference beam, wherein the target beam and the reference beam are coherently combined, the coherently combined beams establishing a difference frequency, and a detector configured to measure the difference frequency.

System and Method for Increasing Resolution of Images Obtained from a Three-Dimensional Measurement System

A system uses range and Doppler velocity measurements from a lidar system and images from a video system to estimate a six degree-of-freedom trajectory (6DOF) of a target. The 6DOF transformation parameters are used to transform multiple images to the frame time of a selected image, thus obtaining multiple images at the same frame time. These multiple images may be used to increase a resolution of the image at each frame time, obtaining the collection of the superresolution images.

MEASUREMENT APPARATUS AND MEASUREMENT METHOD

A measurement apparatus including: a laser that outputs a frequency-modulated laser beam; a branch that splits the frequency-modulated laser beam into a reference light and a measurement light; a beat signal generator that generates a beat signal by mixing the reference light and a reflected light that is reflected by radiating the measurement light onto an object to be measured; a frequency analyzer that frequency-analyzes the beat signal; a storage that stores a reference frequency signal which is a frequency signal obtained by converting a reference signal output by the beat signal generator in a state without the object to be measured; and calculation circuitry that calculates a difference between propagation distances of the reference light and the measurement light. 2. The measurement apparatus according to claim 1 , wherein the beat signal generation part outputs claim 1 , as the reference signal claim 1 , a signal including a reference beat signal generated by mixing the reference light and an end-face reflected light reflected from an exit end face that emits the measurement light.3. The measurement apparatus according to claim 2 , wherein the beat signal generation part generates two beat signals claim 2 , which are (i) a first beat signal due to the reflected light of the measurement light and the reference light and (ii) a second beat signal due to the end-face reflected light and the reference light claim 2 ,the frequency analyzing part outputs, as a distance measurement signal, a signal which is obtained by converting a signal in which the two beat signals generated by the beat signal generation part are superposed into a frequency domain signal, andthe frequency analyzing part subtracts a frequency spectrum of the reference beat signal based on the end-face reflected light from a frequency spectrum of the distance measurement signal by subtracting a signal level of the reference frequency signal from a signal level of the distance measurement signal ...

TECHNIQUES FOR LIDAR SYSTEM NOISE CALIBRATION AND COMPENSATION FOR IMPROVED TARGET DETECTION

A light detection and ranging (LIDAR) system to generate a baseband signal in the time domain from the return signal, where the baseband signal includes frequencies corresponding to LIDAR target ranges; and a signal processing system coupled with the optical processing system to measure energy of the baseband signal in the frequency domain, to compare the energy to an estimate of LIDAR system noise, and to determine a likelihood that an signal peak in the frequency domain indicates a detected target. 1. A method , comprising:generating, in a light detection and ranging (LIDAR) system, a baseband signal from a target return signal when the LIDAR system is in a target detection mode;generating an estimate of system noise in the LIDAR system by measuring the baseband signal when the system is in an anechoic calibration state, the baseband signal comprising frequencies corresponding to LIDAR target ranges;comparing signal peaks of the baseband signal generated to the estimate of system noise in a frequency domain; anddetermining a likelihood that a signal peak, from the signal peaks, indicates a detected target.2. The method of claim 1 , wherein the anechoic calibration state comprises one of an anechoic factory calibration state claim 1 , a low-power boot-up calibration state claim 1 , the anechoic calibration state in an occluded field of view (FOV) claim 1 , or a target-absent calibration state claim 1 , and wherein the signal peaks are based on one or more of signal energy across frequency bins of the baseband signal claim 1 , autocorrelation of the baseband signal across the frequency bins claim 1 , and cross-correlation between the baseband signal and the system noise estimate across the frequency bins.3. The method of claim 2 , wherein the estimate of LIDAR system noise further comprises a measurement of one or more of a noise energy claim 2 , a mean of the noise energy claim 2 , a variance of the noise energy claim 2 , an asymmetry of the noise energy claim 2 , ...

Lidar system target detection

A light detection and ranging (LIDAR) system including a processor to receive a return signal from a target based on an optical beam transmitted towards the target and receive a baseband signal in a time domain based on the return signal. The processor of the LIDAR system further to produce a comparison of signal peaks of the baseband signal with an estimate of LIDAR system noise in the frequency domain, and identify targets based on the comparison.

MIRROR MOVEMENT AND LASER SHOOT PATTERN COMPENSATION FOR FREQUENCY-MODULATED CONTINOUS-WAVE (FMCW) LIDAR

A scanning system includes a transmitter, a scanning structure, and a controller. The transmitter is configured to transmit a frequency modulated continuous wave (FMCW) light beam that includes a plurality of frequency ramps including up-chirps and down-chirps that are matched into up-down chirp pairs. The scanning structure is configured to oscillate about a scanning axis such that a deflection angle of the scanning structure continuously varies over time in an angular range between two maximum deflection angles. The controller is configured to segment the angular range into a plurality of sub-angular ranges and assign each up-down chirp pair to a different sub-angular range of the plurality of sub-angular ranges. Each up-down chirp pair includes an up-chirp transmitted in an assigned sub-angular range during a first scanning movement of the scanning structure and a down-chirp transmitted in the assigned sub-angular range during a second scanning movement of the scanning structure.

Lidar device using time delayed local oscillator light and operating method thereof

A light detection and ranging (LiDAR) device includes a transmitter configured to transmit a continuous wave light to an object and provide a local oscillator (LO) light corresponding to the transmitted continuous wave light; a delay circuit configured to time delay the LO light; a receiver configured to receive the continuous wave light reflected from an object; and a detection circuit configured to determine a distance from the LiDAR device to the object based on the time delayed LO light and the received continuous wave light.

SYSTEMS AND METHODS FOR LINEARIZING NON-LINEAR CHIRP SIGNALS

A light detection and ranging (LiDAR) sensor is described herein. The LiDAR sensor can comprise a fiber optic ending, a laser assembly, and one or more processors. The fiber optic ending can comprise a fiber optic cable terminated by a reflector. The laser assembly can emit a chirp signal to detect an object in an environment. A portion of the chirp signal can be diverted to the fiber optic ending. The one or more processors construct a profile of the chirp signal based on the diverted portion of the chirp signal. The one or more processors determine a best fit curve based on the profile of the chirp signal and one or more parameters associated with the best fit curve. A frequency offset between an emitted chirp signal and a returned chirp signal can be computed based on the best fit curve and the one or more parameters. Based on the frequency offset, the one or more processors can determine a range of the object. 1. A light detection and ranging (LiDAR) system comprising:a fiber optic ending comprising a fiber optic cable terminated by a reflector;a laser assembly that emits a chirp signal to detect an object in an environment, wherein a portion of the chirp signal is diverted to the fiber optic ending; and construct a profile of the chirp signal based on the diverted portion of the chirp signal;', 'determine a best fit curve based on the profile of the chirp signal and one or more parameters associated with the best fit curve;', 'compute a frequency offset between an emitted chirp signal and a returned chirp signal based on the best fit curve and the one or more parameters; and', 'determine a range of the object based on the frequency offset., 'one or more processors configured to2. The LiDAR sensor of claim 1 , wherein the fiber optic cable has a length of at least a detection range of the LiDAR sensor.3. The LiDAR sensor of claim 1 , wherein the reflector reflects the diverted portion of the chirp signal back to the laser assembly through the fiber optic cable.4 ...

Method and device for operating multiple sensors of a vehicle

A method for operating multiple sensors of a vehicle in at least partially spatially coinciding detection areas and in a shared frequency domain. In the method, at a transmission point in time, at least two sensors transmit simultaneously on separate instantaneous frequencies separated by a frequency gap, the frequency gap including at least one instantaneous receive bandwidth of the sensors, each instantaneous frequency being blocked for a use by the sensors after the transmission point in time for the duration of a time gap, the time gap including at least one signal propagation time across a reception range of the sensors.

BEAM WALKOFF MITIGATION FOR LIGHT DETECTION AND RANGING

A light detection and ranging (LIDAR) system includes a first receive optical coupler, a second receive optical coupler, a first optical mixer, a second optical mixer, and an optical switch. The first optical mixer is configured to receive a first receive signal from the first receive optical coupler. The second optical mixer is configured to receive a second receive signal from the second receive optical coupler. The optical switch is configured to switch an oscillator light signal between the first optical mixer and the second optical mixer. 1. A light detection and ranging (LIDAR) system comprising:a first receive optical coupler;a second receive optical coupler;a first optical mixer configured to receive a first receive signal from the first receive optical coupler;a second optical mixer configured to receive a second receive signal from the second receive optical coupler; andan optical switch configured to switch an oscillator light signal between the first optical mixer and the second optical mixer, wherein the first optical mixer is configured to generate a first electrical signal in response to receiving the oscillator light signal and the first receive signal, and wherein the second optical mixer is configured to generate a second electrical signal in response to receiving the oscillator light signal and the second receive signal.2. The LIDAR system of further comprising:a rotating mirror configured to rotate in a first direction when the optical switch is switched to provide the oscillator light signal to the first optical mixer, the rotating mirror configured to rotate in a second direction when the optical switch is switched to provide the oscillator light signal to the second optical mixer, wherein the first direction is opposite of the second direction.3. The LIDAR system of further comprising:processing logic configured to receive a first electrical signal from the first optical mixer when the optical switch is switched to provide the oscillator light ...

MEASUREMENT APPARATUS AND MEASUREMENT METHOD

A measurement apparatus includes a laser apparatus, a branch that branches a frequency-modulated laser beam into a reference light and a measurement light, a beat signal generator that generates a beat signal by mixing the reference light and a reflected light that is the measurement light radiated onto an object to be measured, a first analyzer that analyses a first signal component corresponding to a difference in a propagation distance between the reference light and the measurement light on the basis of the beat signal, a second analyzer that analyses a second signal component corresponding to a cavity frequency of an optical cavity on the basis of the beat signal, and calculation circuitry that calculates the difference in the propagation distance between the reference light and the measurement light. 1. A measurement apparatus comprising:a laser apparatus that has an optical cavity and outputs a frequency-modulated laser beam with a plurality of modes;a branch that branches a first portion of the frequency-modulated laser beam output by the laser apparatus as a reference light and at least some of a remaining second portion of the frequency-modulated laser beam as a measurement light;a beat signal generator that generates a beat signal by mixing the reference light and a reflected light that is reflected by radiating the measurement light onto an object;a first analyzer that analyzes a first signal component corresponding to a difference in a propagation distance between the reference light and the measurement light on the basis of the beat signal;a second analyzer that analyzes a second signal component corresponding to a cavity frequency of the optical cavity on the basis of the beat signal; andcalculation circuitry configured to calculate the difference in the propagation distance between the reference light and the measurement light based on analysis results of the first signal component and the second signal component.2. The measurement apparatus ...

Chirped Coherent Laser Radar System and Method

A laser radar system using collocated laser beams to unambiguously detects a range of a target and a range rate at which the target is moving relative to the laser radar system. Another aspect of various embodiments of the invention may relate to a laser radar system that uses multiple laser radar sections to obtain multiple simultaneous measurements (or substantially so), whereby both range and range rate can be determined without various temporal effects introduced by systems employing single laser sections taking sequential measurements. In addition, other aspects of various embodiments of the invention may enable faster determination of the range and rate of the target, a more accurate determination of the range and rate of the target, and/or may provide other advantages.

Method and system for enhanced velocity resolution and signal to noise ratio in optical phase-encoded range detection

A system and method for enhanced velocity resolution and signal to noise ratio in optical phase-encoded range detection includes receiving an electrical signal generated by mixing a first optical signal and a second optical signal, wherein the first optical signal is generated by modulating an optical signal, wherein and the second optical signal is received in response to transmitting the first optical signal toward an object, and determining a Doppler frequency shift of the second optical signal, and generating a corrected electrical signal by adjusting the electrical signal based on the Doppler frequency shift, and determining a range to the object based on a cross correlation of the corrected electrical signal with a radio frequency (RF) signal that is associated with the first optical signal.

LIDAR SYSTEM BASED ON MULTI-CHANNEL LASER MODULE FOR SIMULTANEOUS BEAM SCANNING OF TARGET ENVIRONMENT

A FMCW LIDAR system for simultaneous beam scanning of the target environment. The system can include a photonics assembly couplable to a beam steering module. The photonics assembly is configured to receive a frequency modulated laser beam and can include an optical splitter and a coherent receiver. The optical splitter can be configured to optically split the frequency modulated laser beam into a local laser beam and a target laser beam, deliver the target laser beam to the beam steering module, and receive the target laser beam reflected by a target from the beam steering module. The coherent receiver can be configured to mix the local laser beam and the target laser beam to produce an output signal. 1. A photonics assembly couplable to a beam steering module , the photonics assembly comprising: [ optically split the frequency modulated laser beam into a local laser beam and a target laser beam;', 'deliver the target laser beam to the beam steering module; and', 'receive the target laser beam reflected by a target from the beam steering module; and, 'an optical splitter couplable to the beam steering module, the optical splitter configured to, receive the local laser beam from the optical splitter;', 'receive the reflected target laser beam from the optical splitter; and', 'mix the local laser beam and the target laser beam to produce an output signal., 'a coherent receiver coupled to the optical splitter, the coherent receiver configured to], 'an optical system configured to receive a frequency modulated laser beam, the optical system comprising2. The photonics assembly of claim 1 , wherein the optical splitter comprises an optical power tap configured to optically split the frequency modulated laser beam into the local laser beam and the target laser beam.3. The photonics assembly of claim 1 , wherein the optical splitter comprises an optical circulator configured to:deliver the target laser beam to the beam steering module;receive the target laser beam ...

Method for measuring the frequency modulation of a laser source

A method for reducing the peak factor of a signal transmitted in a frequency band comprising several channels, the signal using a plurality of channels in the band comprises: a step of clipping the signal, a step of subtracting the clipped signal from the signal, so as to obtain a peak signal, a step of filtering the peak signal with the aid of a multichannel filter configured to comply with a predetermined spectral mask for each of the channels used by the signal, and a step of subtracting the filtered peak signal from the signal. A device for emitting a multichannel signal implementing the method for reducing the peak factor is also provided.

USE OF CONJUGATE FOCAL PLANE TO GENERATE TARGET INFORMATION IN A LIDAR SYSTEM

A light detection and ranging (LIDAR) system includes an optical source to emit an optical beam, where a local oscillator (LO) signal is generated from a partial reflection of the optical beam from a partially-reflecting surface proximate to the first focal plane, and where a transmitted portion of the optical beam is directed toward a scanned target environment. LIDAR system to focus the LO signal and a target return signal at a second focal plane comprising a conjugate focal plane to the first focal plane. The system may also include a photodetector with a photosensitive surface proximate to the conjugate focal plane to mix the LO signal with the target return signal to generate target information. 1. A light detection and ranging (LIDAR) system , comprising:one or more optical components coupled with the optical source to focus an optical beam at a first focal plane, wherein a local oscillator (LO) signal is generated from a partial reflection of the optical beam from a partially reflecting surface proximate to the first focal plane and reflected back through a first lens system to focus the optical beam at the first focal plane, wherein a transmitted portion of the optical beam is directed toward a scanned target environment, the one or more optical components further to focus the LO signal and a target return signal at a second focal plane comprising a conjugate focal plane to the first focal plane; anda photodetector comprising a photosensitive surface proximate to the conjugate focal plane to mix the LO signal with the target return signal to generate target information.2. The system of claim 1 , wherein the partially reflecting surface is an optical window.3. The system of claim 2 , wherein the free-space optics further comprise a second lens system claim 2 , wherein the LO signal is directed through the second lens system by polarization beam splitter (PBS) claim 2 , the second lens system to focus the LO signal and the target return signal at the second ...

Coherent lidar system for automated vehicles

A coherent lidar system suitable for use on an automated vehicle includes a laser-unit, a lens, a coupler, and a polarized-beam-splitter. The laser-unit is used to provide a laser-beam directed toward a target-area and generate a local-oscillator. The local-oscillator is characterized by a reference-polarization. The lens is used to collect reflected-light that is a reflection of the laser-beam by a target present in the target-area. The coupler is used to combine the reflected-light collected by the lens and the local-oscillator to form a composite-beam. The polarized-beam-splitter used to provide a first-beam that corresponds to the composite-beam polarized to a first-polarization, and a second-beam that corresponds to the composite-beam polarized to a second-polarization different from the first-polarization.

Phase error correction in synthetic aperture imaging

A method for phase error correction in a synthetic aperture (SA) imaging system is configured to image a target region of a scene from a platform in relative movement with respect to the scene. The method includes acquiring target SA data from the target region and reference SA data from a reference region of the scene, using a SA acquisition unit. One or more phase correction factors are determined from the reference SA data based on an assumption that the reference region has a known topography. The phase correction factors are representative of uncompensated optical-path-length fluctuations along the optical path between the reference region and the SA acquisition unit mounted on the platform. A phase correction is applied to the target SA data based on the phase correction factors so as to obtain phase-corrected target SA data. A SA imaging system implementing the method is also disclosed.

Methods of linearizing non-linear chirp signals

Systems and methods of linearizing a signal of a light detection and ranging (LiDAR) sensor are described herein. A system receives a portion of a non-linear chirp signal. The portion of the non-linear chirp signal is sampled at a sampling frequency to generate data points corresponding to the portion of the non-linear chirp signal. A profile of the non-linear chirp signal is generated based on the data points. The non-linear chirp signal is linearized based on the profile of the non-linear chirp signal.

Lidar system with semiconductor optical amplifier

In one embodiment, a lidar system includes a light source configured to emit an optical signal. The light source includes a seed laser diode configured to produce a seed optical signal and a semiconductor optical amplifier (SOA) configured to amplify the seed optical signal to produce an amplified seed optical signal, where the emitted optical signal includes the amplified seed optical signal. The light source further includes an electronic driver configured to supply electrical current to the seed laser diode and electrical current to the SOA. The lidar system also includes a receiver configured to detect a portion of the emitted optical signal scattered by a target located a distance from the lidar system. The lidar system further includes a processor configured to determine the distance from the lidar system to the target.

Techniques for range and velocity measurements in a non-degenerate lidar system

A light detection and ranging (LIDAR) system is provided that includes a first optical source and a second optical source configured to emit respectively a first optical beam and a second optical beam that are nondegenerate and are chirped antiphase and at least one tap configured to split each of the first optical beam and the second optical beam to generate a first local oscillator and a second local oscillator. The LIDAR system further includes lensing optics to direct the first and second optical beams toward a target and collect reflected light from the first optical beam and second optical beam incident upon the target into a return path, the reflected light being collected into a return optical beam comprising a first return signal and a second return signal, and a first optical detector and a second optical detector configured to detect a first beat frequency generated from by mixing the first return signal with the first local oscillator and a second beat frequency generated from mixing the second return signal with the second local oscillator.

Lidar system based on complementary modulation of multiple lasers and coherent receiver for simultaneous range and velocity measurement

A LIDAR system and method for determining a distance and a velocity of a target. The LIDAR system can include laser bank ( 62 ) is configured to generate a laser field from a first laser beam having a positive frequency sweep and a second laser beam having a negative frequency sweep, an optical combiner ( 65 ), an optical coupler ( 63 ), a photoreceiver ( 66 ), and a control circuit ( 69 ). The optical coupler direct a first portion of the laser field at the target such that the first portion is reflected by the target to the optical combiner. The optical combiner can optically combine the portions of the laser field. The output an 1-output ( 67 ) and a Q-output ( 68 ) according to the optically combined portions of the laser field. The control circuit can determine a nominal beat frequency, which corresponds to the distance of the target, and a frequency shift, which corresponds to the velocity of the target, accordingly.

Techniques to use convolution to reduce measured error in coherent lidar systems

A first signal is sampled at the LiDAR system to produce a first set of samples around a first detected frequency peak related to the first signal. A second signal is sampled at the LiDAR system to produce a second set of samples around a second detected frequency peak related to the second signal. A first function based on the first set of samples and a second function based on the second set of samples are convolved to produce a third function. At least one of the first signal or the second signal is refined to produce at least one of a first refined signal or a second refined signal based on the third function. Range and velocity information is extracted related to a target based on the at least one of the first refined signal or the second refined signal.

Balanced photodetector and methods thereof

A balanced photodetector may include: a balanced photodetector including a first photodiode and a second photodiode coupled with one another at a common node, wherein the first photodiode has a first effective responsivity and the second photodiode has as second effective responsivity; and a control circuit configured to set an operating parameter of the balanced photodetector to compensate for a difference between the first effective responsivity and the second effective responsivity.

LIDAR SENSOR SYSTEM

A lidar sensor system. The lidar sensor system includes a transmission unit having a laser source, a phase modulator for modulating a phase of the light of the laser source, and a transmission optic for emitting the modulated light; a reception unit having a reception optic for receiving light reflected from an object and having an evaluation unit for evaluating the light received by the reception optic; the transmission unit being embodied to emit several transmission sequences of the light; each transmission sequence having a first portion and a second portion; the first portion being an unmodulated constant-phase signal; the second portion being a signal phase-modulated by the phase modulator; and the evaluation unit being embodied to determine at least an absolute value of a Doppler frequency based on the first portion, and to determine a distance to the object based on the Doppler frequency and the second portion. 1. A lidar sensor system , comprisinga transmission unit having a laser source, a phase modulator configured to modulate a phase of light of the laser source, and a transmission optic configured to emit the light modulated by the phase modulator into an environment of the lidar sensor system; anda reception unit having a reception optic configured to receive light reflected from an object of the environment and having an evaluation unit configured to evaluate the light received by the reception optic;wherein the transmission unit is configured to emit several transmission sequences of the light, each transmission sequence of the transmission sequences having a first portion and a second portion, the first portion being an unmodulated constant-phase signal, and the second portion being a signal phase-modulated by the phase modulator; andwherein the evaluation unit is configured to determine at least an absolute value of a Doppler frequency based on the first portion, and to determine a distance to the object on based on a Doppler frequency and the ...

LIDAR TRANSMIT/RECEIVE SYSTEM

A light detection and ranging (LIDAR) system for a vehicle, includes a laser source configured to generate light signals, a transceiver, and a fiber array coupled to the transceiver and including a plurality of output channels. The transceiver is configured to receive one or more light signals from the laser source through a first group of output channels of the fiber array, receive one or more local oscillator (LO) signals through a second group of output channels of the fiber array, transmit the one or more light signals into an environment of the vehicle, receive a first returned light reflected from one or more objects in the environment, and output the first returned light and a first LO signal of the one or more LO signals. 1. A light detection and ranging (LIDAR) system for a vehicle , the LIDAR system comprising:a laser source configured to generate light signals;a transceiver; anda fiber array coupled to the transceiver and comprising a plurality of output channels, receive one or more light signals from the laser source through a first group of output channels of the fiber array,', 'receive one or more local oscillator (LO) signals through a second group of output channels of the fiber array,', 'transmit the one or more light signals into an environment of the vehicle,', 'receive a first returned light reflected from one or more objects in the environment, and', 'output the first returned light and a first LO signal of the one or more LO signals., 'wherein the transceiver is configured to2. The LIDAR system as recited in claim 1 , wherein the first returned light and the first LO signal have the same polarization.3. The LIDAR system as recited in claim 1 , wherein the one or more LO signals are polarized in a particular angle with reference to a plane of the transceiver.4. The LIDAR system as recited in claim 1 , wherein the one or more LO signals are polarized parallel to the plane of the transceiver.5. The LIDAR system as recited in claim 1 , further ...

SINGLE BEAM DIGITALLY MODULATED LIDAR FOR AUTONOMOUS VEHICLE DISTANCE SENSING

According to one aspect, a relatively low-cost sensor for use on an autonomous vehicle is capable of detecting moving objects in a range or a zone that is between approximately 80 meters and approximately 300 meters away from the autonomous vehicle. A substantially single fan-shaped light beam is scanned for a full 360 degrees in azimuth. Using frequency-modulated-continuous-wave (FMCW) or phase coded modulation on the beam, with back end digital signal processing (DSP), moving objects may effectively be distinguished from a substantially stationary background. 1. A method for performing lidar sensing , comprising:generating a single divergent light beam;scanning the single divergent light beam in an azimuth direction into a target area; andapplying coherent detection based on returned light from the target area to detect one or more objects in the target area.2. The method of claim 1 , wherein generating the single divergent light beam has an elevational component.3. The method of claim 1 , further comprising:based on the coherent detection, deriving a velocity of the one or more objects in the target area.4. The method of claim 1 , wherein the single divergent light beam is a fan-shaped light beam.5. The method of claim 1 , wherein generating the single divergent light beam includes generating the single divergent light beam from a stable light source.6. The method of claim 1 , further comprising applying baseband modulation to the single divergent light beam claim 1 , and wherein applying coherent detection includes recovering a modulation of the returned light and analyzing frequency components of the returned light in order to detect the one or more objects in the target area and a velocity of the one or more objects.7. The method of claim 1 , wherein scanning includes scanning the single divergent beam approximately 360 degrees around a vehicle to detect the one or more objects in the target area with respect to the vehicle.8. The method of claim 1 , wherein ...

FILTER FOR NOISE REDUCTION IN DETECTION IN REMOTE SENSING SYSTEMS

Vehicles, systems, and techniques are provided for noise reduction in detection in remote sensing systems. Noise reduction can be accomplished, in some embodiments, by narrowing a time interval to receive return EM radiation (or, in other embodiments, EM signals representative of the return EM radiation) at a system mounted in a vehicle. The time interval can be narrowed by adjusting the time during which the system can receive the return EM radiation. In other embodiments, rather than adjusting the time interval, a processing unit can remove a portion of data representative of a signal resulting from mixing probe EM radiation and return EM radiation. The data that is removed can be representative of the signal during a leading interval of the defined period during which probe EM radiation is emitted. Such a removal can result in second data representative of the signal during a terminal interval of the defined period. 1. A sensing system , comprising:a transmitter module configured to generate a first electromagnetic signal and emit a first portion of the first electromagnetic signal into an environment proximate to the sensing system during a defined period, the first portion of the first electromagnetic signal being a transmitted electromagnetic signal, the defined period comprises a leading interval and a terminal interval;a receiver module configured to receive a reflected electromagnetic signal responsive to the transmitted electromagnetic signal, the reflected electromagnetic signal corresponding to a reflection of a portion of the transmitted electromagnetic signal by an object in the environment proximate to the sensing system;a mixer module configured to mix the reflected electromagnetic signal received by the receiver module and a second portion of the first electromagnetic signal generated by the transmitter module to output a mixed electromagnetic signal; anda switching component configured to filter the mixed electromagnetic signal such that the ...

Transimpedance amplifier for lidar system

A Lidar system, photonic chip and method of detecting an object. The photonic chip includes a laser and one or more photodetectors. The laser generates a transmitted light beam. The one or more photodetectors are receptive to a reflected light beam that is a reflection of the transmitted light beam from an object and generate an electrical signal as output in response to the reflected light beam signal. An amplifier is configured to amplify a signal related to the reflected light beam to amplify the output signal of the one or more photodetectors. A processor determines a parameter of the object from the amplified output signal.

Dual path light detection and ranging system

A dual path configuration Integrated LiDAR architecture can contain a focal plane transmitter and a focal plane coherent receiver. The integrated LiDAR transmitter can contain an optical frequency chirp generator and a focal plane optical beam scanner with integrated driving electronics. The integrated LiDAR receiver architecture can be implemented with per-pixel coherent detection and amplification.

System and Method for Increasing Coherence Length in Lidar Systems

Various implementations of the invention compensate for “phase wandering” in tunable laser sources. Phase wandering may negatively impact a performance of a lidar system that employ such laser sources, typically by reducing a coherence length/range of the lidar system, an effective bandwidth of the lidar system, a sensitivity of the lidar system, etc. Some implementations of the invention compensate for phase wandering near the laser source and before the output of the laser is directed toward a target. Some implementations of the invention compensate for phase wandering in the target signal (i.e., the output of the laser that is incident on and reflected back from the target). Some implementations of the invention compensate for phase wandering at the laser source and in the target signal. 1. A system for compensating for phase variance of a laser source comprising: a delay line configured to delay an output of the laser source, and', 'a phase modulator configured to receive an output of the delay line and an output of a phase corrector; and, 'a laser output path comprising a phase detector configured to determine an estimated phase error of the laser source, and', 'the phase corrector configured to receive the output of the phase detector and determine a phase correction as the output of the phase corrector,, 'a phase error path comprisingwherein the phase modulator outputs a phase corrected laser output.2. The system of claim 1 , wherein the phase detector is an optical phase detector.3. The system of claim 2 , wherein the optical phase detector comprises:a splitter configured to receive the output of the laser source and output a first output and a second output;a delay line configured to delay the first output; anda phase detector configured to determine a phase difference between the delayed first output and the second output,wherein the optical phase detector outputs the phase error derived from the phase difference as the estimated phase error.4. The system ...

MEASUREMENT APPARATUS AND MEASUREMENT METHOD

A measurement apparatus including a laser apparatus that outputs a frequency-modulated laser beam with a plurality of modes of a main lobe, branch that splits the frequency-modulated laser beam into a reference light, a measurement light, and a monitor light, beat signal generator that generates a beat signal by mixing the reference light and a reflected light that is reflected by radiating the measurement light onto an object to be measured, extraction circuitry that extracts a signal component including a plurality of self-beat signals based on the main lobe from the monitor light, identification circuitry that identifies a cavity frequency of the optical cavity on the basis of the signal component, and calculation circuitry that calculates a difference between propagation distances between the reference light and the measurement light on the basis of the cavity frequency and the beat signal. 1. A measurement apparatus comprising:a laser apparatus, having a frequency shifter in an optical cavity, that outputs a frequency-modulated laser beam with a plurality of modes of a main lobe;a branch that splits the frequency-modulated laser beam output from the laser apparatus into a reference light, a measurement light, and a monitor light;a beat signal generator that generates a beat signal by mixing the reference light and a reflected light that is reflected by radiating the measurement light onto an object to be measured;extraction circuitry configured to extract a signal component including a plurality of self-beat signals based on the main lobe from an electrical signal generated by converting the monitor light;identification circuitry configured to identify a cavity frequency of the optical cavity on the basis of the signal component extracted by the extraction circuitry; andcalculation circuitry configured to calculate a difference between propagation distances of the reference light and the measurement light on the basis of the cavity frequency of the optical ...

Laser radar device and method for controlling frequency modulation

The laser radar device includes: a modulated light generator configured to generate modulated laser light using frequency modulation based on a control parameter; an optical combiner configured to combine the received light and the local light to generate interference light; a photodetector configured to detect the interference light and output an electrical signal; a frequency-to-voltage converter configured to convert the electrical signal into a voltage signal; a characteristic calculator configured to measure a characteristic value of the voltage signal; an evaluator configured to evaluate, on a basis of the characteristic value, whether a center frequency of a spectrum of a return signal component is within a range of a demodulation band of a demodulation circuit; and a parameter setting unit configured to change the control parameter when it is evaluated that the center frequency is not within the range of the demodulation band.

ELECTRO-OPTICAL DISTANCE METER AND METHOD FOR CALCULATING OPTICAL NOISE SIGNAL

An electro-optical distance meter measures an electrical noise signal in a state where a received light amount adjusting means completely blocks light and measure a distance-measuring signal under a proper state of the adjusting means to calculate a distance by subtracting the electrical noise signal and an optical noise signal from the distance-measuring signal. The distance meter measures a first noise signal in a state where the adjusting means completely blocks light with a noise measuring jig having a unique jig-derived noise signal attached and a second noise signal in a state where the adjusting means transmits light most with the noise measuring jig attached, to calculate the optical noise signal by subtracting the first noise signal and the jig-derived noise signal from the second noise signal. The noise measuring jig is detachably attached to the electro-optical distance meter and removes reflected light entering the light receiving element when attached. 1. An electro-optical distance meter comprising:a first light source configured to emit distance-measuring light toward a measuring object;a first light receiving unit including a first light receiving element configured to receive the distance-measuring light reflected by the measuring object and convert the distance-measuring light into a distance-measuring signal, and a first received light amount adjusting means configured to adjust a light amount entering the first light receiving element;a first objective lens configured to condense the reflected distance-measuring light to the first light receiving unit;a first arithmetic control unit configured to calculate a distance to the measuring object from an initial phase of the distance-measuring signal; anda first storage unit configured to store the distance-measuring signal, distance value data, and an optical noise signal, andconfigured to measure an electrical noise signal by putting the first received light amount adjusting means into a state where ...

DISTRIBUTED VEHICLE LIDAR SYSTEM

A distributed FM LiDAR system that provides a central unit that includes a frequency modulated optical signal source and a central receiver for reflected light, along with multiple optical heads that include only optical components is described. No optical delay lines or timing compensation photonic or electronic circuitry is necessary between the central unit and the optical heads. The relatively simple optical heads do not require extensive protection from shock or vibration, and can be distributed between a vehicle and a towed trailer or similar vehicle, with connections being provided by an optical coupling. 1. A distributed lidar system , comprising: a frequency modulated light source in the housing, the frequency modulated light source configured to provide a frequency modulated waveform; and', 'a receiver in the housing, the receiver configured to transform a reflected frequency modulated waveform into an electrical signal; and, 'a signal processing unit in a housing, the signal processing unit comprising an optical scanner in optical communication with the frequency modulated light source, the optical scanner configured to transmit the frequency modulated waveform into an environment; and', 'an optical input in optical communication with the receiver, the optical input configured to receive the reflected frequency modulated waveform from the environment; and, 'an optical head separate from the housing, the optical head comprisingat least one waveguide that provides optical communication between the signal processing unit and the optical head.2. The distributed lidar system of claim 1 , the frequency modulated light source comprising a laser source optically coupled to a whispering gallery mode optical resonator.3. The distributed lidar system of claim 1 , the signal processing unit further comprising:a controller in the housing, the controller configured to derive information indicative of a distance to an object in the environment based on the electrical ...

TIME OF FLIGHT SENSING SYSTEM AND IMAGE SENSOR USED THEREIN

An image sensor employed in a time-of-flight (TOF) sensing system includes a pixel array including plural pixels, each pixel including at least one photo diode and each pixel generating an amount of charge corresponding to an incident light, comparing circuitry configured to compare voltage levels, each voltage level individually changed based on the amount of charge outputted from each pixel, with a reference voltage to output a comparison result, and calibration circuitry configured to adjust the voltage levels equally based on the comparison result. 1. An image sensor employed in a time-of-flight (TOF) sensing system , comprising:a pixel array including plural pixels, each pixel including at least one photo diode and each pixel generating an amount of charge corresponding to an incident light;comparing circuitry configured to compare voltage levels, each voltage level individually changed based on the amount of charge outputted from each pixel, with a reference voltage to output a comparison result; andcalibration circuitry configured to adjust the voltage levels equally based on the comparison result.2. The image sensor according to claim 1 , wherein the calibration circuitry is configured to maintain a difference between the voltage levels when adjusting the voltage levels by a predetermined amount.3. The image sensor according to claim 1 , wherein the calibration circuitry is further configured to supply a preset amount of current into the pixel array.4. The image sensor according to claim 1 , wherein the pixel comprises:a reset gate coupled to the at least one photo diode and configured to reset the amount of charge in response to a reset signal;a transfer gate configured to output a pixel voltage based on the amount of charge in response to a modulation signal;an access gate configured to be turned on in response to the pixel voltage transferred from the transfer gate; anda select gate configured to selectively output a voltage outputted from the access gate ...

TECHNIQUES FOR MODE AREA EXPANSION OF OPTICAL BEAM IN A LIDAR SYSTEM

A light detection and ranging (LIDAR) apparatus is provided that includes an optical source to emit an optical beam towards a target and a mode field expander operatively coupled to the optical source to expand a mode area of the optical beam from a first mode of a single mode optical fiber to a second mode of a larger mode area optical fiber. 1. A frequency modulated continuous-wave (FMCW) light detection and ranging (LIDAR) apparatus , comprising:an optical source to emit an optical beam towards a target; anda mode field expander operatively coupled to the optical source to expand a mode area of the optical beam from a first mode of a single mode optical fiber to a second mode of a larger mode area optical fiber.2. The FMCW LIDAR apparatus of claim 1 , wherein the mode field expander comprises an adiabatic mode expander.3. The FMCW LIDAR apparatus of claim 1 , further comprising:a first beam separator operatively coupled between the optical source and the mode field expander, the first beam separator to separate a first portion of the optical beam in a first direction towards the target and a second portion of the optical beam in a second direction as a local oscillator signal.4. The FMCW LIDAR apparatus of claim 3 , further comprising:a beam combiner to generate a combined signal comprising the local oscillator signal and a target signal associated with the optical beam.5. The FMCW LIDAR apparatus of claim 4 , further comprising:a photodetector operatively coupled to the beam combiner to receive the combined signal from the beam combiner.6. The FMCW LIDAR apparatus of claim 4 , wherein the mode field expander is operatively coupled between at least one optical device and the beam combiner claim 4 , wherein the mode field expander receives the target signal from the at least one optical device claim 4 , expands the mode area of the target signal and provides the target signal to the beam combiner.7. The FMCW LIDAR apparatus of claim 1 , further comprising:a ...

TECHNIQUES FOR AMPLIFICATION OF RETURN SIGNAL IN LIDAR SYSTEM

A light detection and ranging (LIDAR) apparatus includes an optical circuit including an optical source to transmit an optical beam, a first optical component to generate a local oscillator from the optical beam, a first optical amplifier to amplify a return signal to generate an amplified return signal, wherein a power level of the local oscillator is comparable to a power of amplified spontaneous emission of the first optical amplifier, and an optical detector operatively coupled to the first optical amplifier, the optical detector configured to output an electrical signal based on the amplified return signal and the local oscillator. 1. A light detection and ranging (LIDAR) apparatus , comprising:an optical source to transmit an optical beam;a first optical component to generate a local oscillator from the optical beam;a first optical amplifier to amplify a return signal to generate an amplified return signal, wherein a power level of the local oscillator is comparable to a power of amplified spontaneous emission of the first optical amplifier; andan optical detector operatively coupled to the first optical amplifier, the optical detector configured to output an electrical signal based on the amplified return signal and the local oscillator.2. The LIDAR apparatus of claim 1 , wherein the first optical amplifier comprises a semiconductor optical amplifier.3. The LIDAR apparatus of claim 1 , the optical detector comprising:a beam combiner operatively coupled to an output of the first optical amplifier, the beam combiner configured to receive a local oscillator signal;a photodetector operatively coupled to the beam combiner; andan amplifier operatively coupled to the photodetector, the amplifier configured to output the electrical signal.4. The LIDAR apparatus of claim 1 , wherein the first optical component comprises a polarizing beam splitter.5. The LIDAR apparatus of claim 1 , wherein the first optical component comprises a circulator.6. The LIDAR apparatus of ...

Distance Measurement by Means of an Active Optical Sensor System

A method for distance measurement by means of an active optical sensor system is disclosed, comprising: an initial pulse sequence with an initial frequency spectrum, which corresponds to a frequency comb, is generated using a laser source. Based thereon, a first pulse sequence and a first reference pulse sequence with a first frequency spectrum, which corresponds to a first part of the frequency comb, as well as a second pulse sequence and a second reference pulse sequence with a second frequency spectrum, which corresponds to a second part of the frequency comb, are generated. A first distance of the object is determined using a first heterodyne measurement based on the first reference pulse sequence and reflected portions of the first pulse sequence and a second distance is determined using a second heterodyne measurement based on the second reference pulse sequence and reflected portions of the second pulse sequence. 1. A method for distance measurement using an active optical sensor system , comprising:generating an initial pulse sequence with an initial frequency spectrum, which corresponds to a frequency comb, using a laser source, wherein the frequency comb comprises a plurality of modes with a respective mode frequency;generating a first pulse sequence with a first frequency spectrum, which corresponds to a first part of the frequency comb, and a first reference pulse sequence with the first frequency spectrum based on the initial pulse sequence;generating a second pulse sequence with a second frequency spectrum, which corresponds to a second part of the frequency comb different from the first part, and a second reference pulse sequence with the second frequency spectrum based on the initial pulse sequence;emitting the first pulse sequence and the second pulse sequence towards an object;determining a first distance of the object from the sensor system using at least one first heterodyne measurement based on the first reference pulse sequence and portions of ...

Underwater lidar

The disclosure relates in some aspects to Light Detection and Ranging (LIDAR) for underwater applications. An exemplary LIDAR system described herein uses a green and/or blue semiconductor laser, which is self-injection locked using a high-quality factor micro-resonator, such as a whispering gallery mode (WGM) resonator. The self-injection locking results in a single mode operation of the laser and reduction of its linewidth. The self-injection allows transferring frequency modulation from the optical micro-resonator to the laser frequency without significant impact on the power of the laser. In some examples, the LIDAR operates in a continuous wave frequency modulated (CWFM) mode. The CWFM LIDAR may be used for ranging, velocity determination, etc., particularly for underwater applications and may be mounted to watercraft or to aircraft designed to fly over water to take underwater measurements.

Lidar system based on light modulator and coherent receiver for simultaneous range and velocity measurement

A LIDAR system and method for determining a distance and a velocity of a target. The LIDAR system can include a N laser modulated by a laser modulator, an optical combiner, an optical splitter, a photoreceiver, and a control circuit. The optical splitter can optically split the modulated laser beam into a first laser beam and a second laser beam and direct the first laser beam at the target such that the first laser beam is reflected by the target to the optical combiner. The optical combiner can optically combine the first laser beam and the second laser beam. The output an I-output and a Q-output according to the optically combined first laser beam and second laser beam. The control circuit can determine a nominal beat frequency, which corresponds to the distance of the target, and a frequency shift, which corresponds to the velocity of the target, accordingly.

LIDAR AND LASER MEASUREMENT TECHNIQUES

A dual-comb measuring system is provided. The dual comb measuring system may include a bi-directional mode-locked femtosecond laser, a high-speed rotation stage, and a fiber coupler. The high-speed rotation stage may be coupled to a pump diode. 1. A dual-comb measuring system comprising:a bidirectional mode-locked femtosecond laser; 'wherein the high-speed rotation stage is coupled to a pump diode; and', 'a high-speed rotation stage;'}a fiber coupler.2. The dual-comb measuring system of claim 1 , wherein the bi-directional mode-locked femtosecond laser is placed on the high-speed rotation stage.3. The dual-comb measuring system of claim 1 , wherein the bidirectional mode-locked femtosecond laser may generate two laser outputs.4. The dual-comb measuring system of claim 3 , wherein the two laser outputs may be combined.5. The dual-comb measuring system of claim 4 , wherein the two laser outputs may be combined using a standard fiber coupler.6. The dual-comb measuring system of claim 3 , wherein the two laser outputs may share a cavity.7. The dual-comb measuring system of claim 3 , wherein the two laser outputs may be mutually coherent in the nature.8. The dual-comb measuring system of claim 1 , wherein the high-speed rotation stage includes a fiber rotary joint.9. The dual-comb measuring system of claim 8 , wherein the fiber rotary joint facilitates the decoupling of a pump fiber from a cavity rotation.10. The dual-comb measuring system of claim 1 , where the measuring system utilizes Sagnac effect.11. The dual-comb measuring system of claim 1 , wherein the high-speed rotation stage has a speed of 10 claim 1 ,000 rpm.12. The dual-comb measuring system of claim 1 , wherein the high-speed rotation stage has a speed of 50 claim 1 ,000 rpm.13. A dual-sideband FMCW LiDAR system comprising:a modulated light generation unit;a transceiver unit; anda control and processing unit.14. The dual-comb measuring system of claim 13 , wherein the modulated light generation unit further ...

System and Method for Calibrating Video and Lidar Subsystems

A system uses range and Doppler velocity measurements from a lidar system and images from a video system to estimate a six degree-of-freedom trajectory of a target. The system calibrates the lidar subsystem with the video subsystem in two stages. In a first stage, the system calibrates the lidar subsystem so that lidar measurements provide 3D lidar coordinates. In a second stage, the system relates the 3D lidar coordinates with a video image obtained from the video subsystem.

SPATIAL PROFILING SYSTEM AND METHOD

Described herein is a system, a method and a processor-readable medium for spatial profiling. In one arrangement, the described system includes a light source configured to provide outgoing light having at least one time-varying attribute at a selected one of multiple wavelength channels, the at least one time-varying attribute includes either or both of (a) a time-varying intensity profile and (b) a time-varying frequency deviation, a beam director configured to spatially direct the outgoing light into one of multiple directions in two dimensions into an environment having a spatial profile, the one of the multiple directions corresponding to the selected one of the multiple wavelength channels, a light receiver configured to receive at least part of the outgoing light reflected by the environment, and a processing unit configured to determine at least one characteristic associated with the at least one time-varying attribute of the reflected light at the selected one of the multiple wavelengths for estimation of the spatial profile of the environment associated with the corresponding one of the multiple directions. 1. A spatial profiling system including:a light source configured to provide outgoing light at a plurality of wavelength channels, including first outgoing light having at least one time varying attribute at a first wavelength channel and to provide second outgoing light having at least one time varying attribute at a second wavelength channel, different to the first wavelength channel, the at least one time varying attribute including at least one of: (a) an intensity profile modulated according to one or more coding sequences and (b) time-varying frequency deviation;a beam director configured to spatially direct the outgoing light into an environment having a spatial profile, wherein the spatial direction is based on wavelength and includes directing the first outgoing light in a first direction and directing the second outgoing light in a second ...

Distance measuring sensor

A distance measuring sensor includes: a light source having a semiconductor optical amplifier and a resonator with a silicon photonic circuit, which are at a semiconductor substrate; a plurality of emitters, each emitter configured to emit a light beam generated by the light source to outside of the light source; a scanner configured to perform scanning with the light beam by enabling the light beam emitted from the light source to be reflected at a mirror and vibrating the mirror; an optical receiver configured to receive a reflected light beam, which is generated by the light beam reflected at the object; and a processor configured to measure the distance to the object based on the reflected light beam received at the optical receiver. Light beams respectively emitted from the emitters are incident on the mirror in different directions. The scanner performs scanning different regions with the respective light beams.

TECHNIQUES FOR IDENTIFYING OBSTRUCTIONS IN A LIDAR SYSTEM

A light detection and ranging (LIDAR) system, includes an optical source to generate a frequency modulated continuous wave (FMCW) optical beam, a memory, and a processor, operatively coupled to the memory, to identify energy peaks in a frequency domain of a range-dependent baseband signal that corresponds to a return signal from a reflection of the FMCW optical beam and identify an obstruction of the LIDAR system based on a comparison of a frequency of the energy peaks to a threshold frequency. 1. A light detection and ranging (LIDAR) system , comprising:an optical source to generate a frequency modulated continuous wave (FMCW) optical beam;a memory; and identify energy peaks in a frequency domain of a range-dependent baseband signal that corresponds to a return signal from a reflection of the FMCW optical beam; and', 'identify an obstruction of the LIDAR system based on a comparison of a frequency of the energy peaks to a threshold frequency., 'a processor, operatively coupled to the memory, to2. The LIDAR system of claim 1 , wherein the processor is further to generate a field of view (FOV) reflectivity map of an FOV of the LIDAR system based on the identification of the obstruction.3. The LIDAR system of claim 1 , wherein the FOV reflectivity map comprises a reflectivity contour at each elevation angle and each azimuth angle of the LIDAR system.4. The LIDAR system of claim 1 , wherein the processor is further to determine an operational effect of the obstruction on the LIDAR system.5. The LIDAR system of claim 4 , wherein claim 4 , to determine the operational effect of the obstruction on the LIDAR system claim 4 , the processor is to calculate a detection range of the LIDAR system based on the return signal and a signal-to-noise ratio of the return signal.6. The LIDAR system of claim 4 , wherein claim 4 , to determine the operational effect of the obstruction on the LIDAR system claim 4 , the processor is to identify portions of a field of view (FOV) of the ...

FREQUENCY CHIRP FOR LIDAR FOR HIGH-VELOCITY TARGETS

A device includes a controller with a processor and memory with instructions for controlling power to a light source such that the light source emits a frequency-modulated continuous light beam that, over time, includes an up region, a down region, and a flat region. The up region includes increasing a frequency of the continuous light beam, the down region includes decreasing the frequency of the continuous light beam, and the flat region includes maintaining the frequency of the continuous light beam at a constant frequency. 1. A method comprising:emitting a frequency-modulated continuous light beam that, over time, includes an up region, a down region, and a flat region, wherein the up region includes increasing a frequency of the continuous light beam, the down region includes decreasing the frequency of the continuous light beam, and the flat region includes maintaining the frequency of the continuous light beam at a constant frequency;detecting backscattered light;determining a magnitude based at least in part on the detected backscattered light responsive to the flat region; anddetermining, based at least in part on the determined magnitude, a velocity of a target.2. The method of claim 1 , wherein the first detected frequency is a range frequency.3. The method of claim 2 , wherein the second detected frequency is a Doppler frequency.4. The method of claim 1 , wherein the frequency during the up region increases linearly claim 1 , wherein the frequency during the down region decreases linearly.5. The method of claim 1 , wherein the up region lasts for a first period of time claim 1 , the down region lasts for a second period of time claim 1 , and the flat region lasts for a third period of time claim 1 , wherein the third period of time is equal to or shorter than either of the first period of time or the second period of time.6. The method of claim 5 , wherein the third period of time is 2 microseconds or less.7. The method of claim 1 , wherein the up region ...

Dual waveforms for three-dimensional imaging systems and methods thereof

A three-dimensional imaging system includes an image intensification subsystem and an illumination subsystem that are both capable of operating with sinusoidal or pulsed waveforms in accordance with phase-measuring or flash modes of operation, respectfully, of the three-dimensional imaging system.

Apparatus and method for detecting target

An apparatus for detecting a target is disclosed. The apparatus of detecting a target includes: a frequency mixer configured to calculate a first beat frequency based on a transmitted signal and a received signal of first scanning and calculate a second beat frequency based on a transmitted signal and a received signal of second scanning performed with a predetermined time interval from the first scanning; a controller configured to extract a first moving component by comparing an up-chirp period frequency and a down-chirp period frequency of at least one of the first beat frequency or the second beat frequency; extract a second moving component by comparing up-chirp period frequencies or down-chirp period frequencies of the first beat frequency and the second beat frequency; and determine the moving target based on the first moving component and the second moving component.

LIDAR SYSTEM

A light detection and ranging (“LIDAR”) system includes a coherent light source that generates a frequency modulated optical signal comprising a series of optical chirps. A scanning assembly transmits the series of optical chirps in a scan pattern across a scanning region, and receives a plurality of reflected optical chirps corresponding to the transmitted optical chirps that have reflected off one or more objects located within the scanning region. A photodetector mixes the reflected optical chirps with a local oscillation (LO) reference signal comprising a series of LO reference chirps. An electronic data analysis assembly processes digital data derived from the reflected optical chirps and the LO reference chirps mixed at the photodetector to generate distance data and optionally velocity data associated with each of the reflected optical chirps. 1229-. (canceled)230. A light detection and ranging (LiDAR) system , comprising:a laser for generating light;a scanning assembly that (a) transmits the light in a scan pattern across a scanning region and (b) receives reflected light that has reflected off one or more objects located within the scanning region; andan electronic data analysis and control assembly that (a) generates a plurality of data points each of which comprises distance data associated with a portion of the reflected light and (b) generates the scan pattern to be used by the scanning assembly based on one or more scan parameters, wherein the scan parameters identify (i) a frame size comprising either a full frame size or a reduced frame size, (ii) a spatial resolution for the identified frame size, and (iii) a non-zero offset for the reduced frame size relative to the full frame size.231. The LiDAR system of claim 230 , wherein the full frame size is larger than the reduced frame size.232. The LiDAR system of claim 230 , wherein the spatial resolution defines the number of scan lines and the number of pixels per scan line for a particular frame size. ...

SYSTEM AND METHOD FOR REFINING COORDINATE-BASED THREE-DIMENSIONAL IMAGES OBTAINED FROM A THREE-DIMENSIONAL MEASUREMENT SYSTEM

A system uses range and Doppler velocity measurements from a lidar system and images from a video system to estimate a six degree-of-freedom trajectory of a target and generate a three-dimensional image of the target. The system may refine the three-dimensional image by reducing the stochastic components in the transformation parameters between video frame times. 12-. (canceled)3. A system for refining 3D images , the system comprising:a lidar subsystem configured to direct at least two beams toward a target, generate a first set of line scan 3D measurements for a plurality of points on the target for a first beam of the at least two beams, and generate a second set of overscan 3D measurements for the plurality of points on the target for a second beam of the at least two beams;a video subsystem configured to provide a set of video frames of the target; and receive, from the lidar subsystem, the first set of line scan 3D measurements and the second set of overscan 3D measurements,', 'receive, from the video subsystem, the set of video frames of the target,', 'determine, at each frame time, a plurality of Δz offsets between pre-overscan measurements and the line scan 3D measurements and between post-overscan measurements and the line scan 3D measurements, and', 'adjust a plurality of transformation parameters based on a least square optimization and the plurality of Δz offsets., 'a processor configured to4. The system of claim 3 , wherein the pre-overscan measurements correspond to those measurements from the second set of overscan measurements taken during the inter-frame time interval immediately before said each frame time and wherein the post-overscan measurements correspond to those measurements from the second set of overscan measurements taken during the inter-frame time interval immediately after said each frame time.5. A method for refining 3D images claim 3 , the method comprising:receiving, from a lidar subsystem configured to direct at least two beams ...

MULTICHANNEL ANALOG-DIGITAL CONVERTER DEVICE FOR AN OPTOELECTRONIC SENSOR, METHOD FOR SIGNAL MODULATION IN AN OPTOELECTRONIC SENSOR AND LASER-BASED DISTANCE AND/OR SPEED SENSOR

A multichannel analog-digital converter device for an optoelectronic sensor, including: an analog-digital converter unit; and a plurality of signal processing channels, the signal processing channels of the plurality of signal processing channels each having: a detection antenna to receive optical signals that are reflected by a pixel of an object, a combining unit to combine the detected optical signals with a modulated reference signal, a modulator to produce an individual signal coding, and a photodetector, signals having individual signal coding of the plurality of signal processing channels being capable of being transmitted together to the analog-digital converter unit. 111-. (canceled)12. A multichannel analog-digital converter device for an optoelectronic sensor , comprising:an analog-digital converter unit; anda plurality of signal processing channels; a detection antenna to receive optical signals; and', 'a modulator to provide an individual signal coding;', 'wherein signals having individual signal coding of the plurality of signal processing channels are transmittable together to the analog-digital converter unit., 'wherein each of the signal processing channels of the plurality of signal processing channels include13. The multichannel analog-digital converter device of claim 12 , wherein the signal processing channels of the plurality of signal processing channels each having a photodetector and/or a combining unit claim 12 , and wherein the combining unit is configured to combine the optical signals received by the detection antennas with a modulated reference signal that is receivable by a branched-off reference channel.14. The multichannel analog-digital converter device of claim 13 , wherein the modulator is situated respectively between the detection antenna and the combining unit and/or between the branched-off reference channel and the combining unit and/or between the combining unit and the photodetector and/or between the photodetector and the ...

Multiple laser, single resonator lidar

Various technologies described herein pertain to multiple laser, single optical resonator lidar systems. A lidar system includes a single optical resonator optically coupled to at least a first laser and a second laser. The optical resonator is formed of an electrooptic material. The first laser and the second laser are optically injection locked to the optical resonator. Moreover, a modulator applies a time-varying voltage to the optical resonator to control modulation of an optical property of the electrooptic material, which causes the first laser to generate a first frequency modulated optical signal comprising a first series of optical chirps and/or the second laser to generate a second frequency modulated optical signal comprising a second series of optical chirps. Further, front end optics transmits at least a portion of the first frequency modulated optical signal and/or the second frequency modulated optical signal into an environment from the lidar system.

Direction and doppler shift in ranging systems and methods

Techniques are disclosed for systems and methods to provide accurate and reliable target information when there is relative motion between a remote sensing system and the target. A remote sensing system includes a multichannel ranging sensor assembly and a controller. The ranging sensor assembly includes multiple sensor channels configured to emit modulated sensor beams towards a target and to detect corresponding reflected beams reflected from the target, where the modulated sensor beams are selected to be correlated to each other and mutually incoherent with respect to each other. The controller is configured to receive reflected beam sensor signals corresponding to the detected reflected beams, to determine Doppler components associated with the reflected beams based, at least in part, on the first and second reflected beam sensor signals, and to generate target information based, at least in part, on the determined Doppler components.

HIGHLY MULTIPLEXED COHERENT LIDAR SYSTEM

A light detection and ranging (LIDAR) system comprises a laser diode; a laser diode driver circuit configured generate a laser beam using the laser diode and to frequency chirp the generated laser beam according to a frequency chirp period; a laser splitter to split the generated laser beam into N transmit laser beams pointed at different angles, wherein N is an integer greater than one, and a frequency chirp period of each of the N transmit laser beams is the frequency chirp period of the generated laser beam; and multiple return beam paths to receive N return beams and determine time of flight values for the N return beams in parallel. 1. A light detection and ranging (LIDAR) system , the system comprising:a laser diode;a laser diode driver circuit configured to generate a laser beam using the laser diode and to frequency chirp the generated laser beam according to a frequency chirp period;a laser splitter configured to split the generated laser beam into N transmit laser beams pointed at different angles, wherein N is an integer greater than one, and a frequency chirp period of each of the N transmit laser beams is the frequency chirp period of the generated laser beam; andmultiple return beam paths to receive N return beams and determine time of flight values for the N return beams in parallel.2. The system of claim 1 , wherein the laser splitter is configured to split the generated laser beam into N transmit laser beams arranged as a two-dimensional grid of N laser beams.3. The system of claim 2 , including a beam steering mechanism configured to steer the two-dimensional grid of N laser beams to multiple scan positions; andwherein the multiple return beam paths are configured to receive N return beams for the multiple scan positions.4. The system of claim 1 , wherein the laser splitter is configured to split the generated laser beam into N transmit laser beams in one dimension as a line of N transmit laser beams.5. The system of claim 4 , including a beam ...

LIGHTING DEVICE FOR FREQUENCY-MODULATED EMISSION

Lighting devices and methods of manufacture are described. A lighting device includes a substrate, multiple light-emitting diodes (LEDs) on the substrate, an electronic switch on the substrate, and multiple connectors, each comprising a wire bond. Multiple wire bonds electrically couple at least two of the multiple LEDs and multiple wire bonds electrically couple the electronic switch and at least one of the plurality of LEDs. 1. A lighting device comprising:a substrate;multiple light-emitting diodes (LEDs) on the substrate;an electronic switch on the substrate; andmultiple connectors each comprising a wire bond,multiple wire bonds electrically coupling at least two of the multiple LEDs and multiple wire bonds electrically coupling the electronic switch and at least one of the plurality of LEDs.2. The lighting device according to claim 1 , wherein the multiple LEDs are adjacent each other on the substrate.3. The light device according to claim 2 , wherein the multiple LEDs form a matrix of LEDs on the substrate.4. The lighting device according to claim 1 , wherein the substrate further comprises conductive tracks claim 1 , and each of the multiple connectors further comprises one of the conductive tracks.5. The lighting device according to claim 4 , wherein the conductive tracks comprise at least one of an anode track and a cathode crack.6. The lighting device according to claim 5 , wherein the at least one of the anode track and the cathode track at least partially surrounds the multiple LEDs on the substrate.7. The lighting device according to claim 6 , wherein the multiple wire bonds that electrically couple the at least two of the multiple LEDs are connected between each of the at least two of the multiple LEDs and one of the anode track and the cathode track.8. The light device according to claim 7 , wherein the multiple wire bonds that electrically couple the electronic switch and the at least one of the plurality of LEDs are connected between the electronic ...

Range finding method, range finding apparatus, and range finding system

A method of finding a range to a target object includes extracting a signal component from a beat signal obtained by synthesizing a transmission wave irradiated onto the target object and a reflection wave reflected and received from the target object, generating a matching evaluation value of a plurality of image data of the target object captured by an imaging device, fusing the signal component and the matching evaluation value before generating a distance image from the matching evaluation value, and setting distance information for each pixel of the image data of the target object based on the signal component and the matching evaluation value fused together to generate a distance image.

METHOD AND SYSTEM FOR TIME SEPARATED QUADRATURE DETECTION OF DOPPLER EFFECTS IN OPTICAL RANGE MEASUREMENTS

In some implementations, a light detection and ranging (LIDAR) system includes a transmitter configured to transmit an optical signal that is output from a laser and modulated based on a modulating signal, a receiver configured to receive a returned optical signal in response to transmitting the optical signal, and a processor. The processor is configured to produce a first optical signal based on the returned optical signal and a first version of the modulating signal, produce a second optical signal based on the returned optical signal and a second version of the modulating signal, generate a digital signal based on the first optical signal and the second optical signal, determine a Doppler frequency shift of the returned optical signal based, at least in part, on the digital signal, and provide data indicative of the Doppler frequency shift to a vehicle. 1. A light detection and ranging (LIDAR) system comprising:a transmitter configured to transmit an optical signal that is output from a laser and modulated based on a modulating signal;a receiver configured to receive a returned optical signal in response to transmitting the optical signal; produce a first optical signal based on the returned optical signal and a first version of the modulating signal;', 'produce a second optical signal based on the returned optical signal and a second version of the modulating signal;', 'generate a digital signal based on the first optical signal and the second optical signal;', 'determine a Doppler frequency shift of the returned optical signal based, at least in part, on the digital signal; and', 'provide data indicative of the Doppler frequency shift to a vehicle., 'a processor configured to2. The LIDAR system according to claim 1 , wherein the processor is further configured to operate the vehicle based on the Doppler frequency shift.3. The LIDAR system according to claim 1 , further comprising mix, during a first time interval, the returned optical signal with a first ...

Laser transmitting and receiving module for lidar

A laser transmitting and receiving module for a light detection and ranging (LiDAR) may include a laser light source; a transmission optical phased array (OPA) device configured to emit laser light from the laser light source into a two-dimensional (2D) area; a reception OPA device configured to receive reflected laser light after being emitted by the transmission OPA device; a mixer configured to mix the laser light with the reflected laser light received by the reception OPA device; and a photo detector configured to detect an optical signal mixed by the mixer.

LIDAR SENSING ARRANGEMENTS

System and methods for Light Detecting and Ranging (LIDAR) are disclosed. The LIDAR system includes a light source that is configured project a beam at various wavelengths toward a wavelength dispersive element. The wavelength dispersive element is configured to receive the beam and direct at least a portion of the beam into a field of view (FOV) at an angle dependent on frequency. The system also includes a detector that is positioned to receive portions of the beam reflected from an object within the FOV and a processor that is configured to control the light source and determine a velocity of the object. 1. A light detecting and ranging (LIDAR) system , the system comprising:a light source configured to generate a beam having discrete frequencies at different times;a wavelength dispersive element positioned to receive at least a portion of the beam and configured to sweep the beam over a range of angles in a field of view (FOV), wherein each discrete frequency of the beam corresponds to a different angle in the FOV;a detector positioned to receive portions of the beam that are reflected from an object within the FOV and configured to generate an object signal based on the received portions of the beam; and cause the beam to sweep from a first frequency at a first time to a second frequency over a ramp up time period;', 'cause the beam to sweep from the second frequency back to the first frequency over a ramp down time period; and', 'determine a velocity of the object based on characteristics of the beam., 'a processor communicably coupled to the detector, the processor configured to2. The system of claim 1 , wherein to determine the velocity of the object claim 1 , the processor is further configured to:identify a first portion of the object signal that corresponds to the object detected during the ramp up time period; andidentify a second portion of the object signal that corresponds to the object detected during the ramp down time period.3. The system of claim ...

Lidar system for autonomous vehicle

Techniques for controlling an autonomous vehicle with a processor that controls operation, includes operating a Doppler LIDAR system to collect point cloud data that indicates for each point at least four dimensions including an inclination angle, an azimuthal angle, a range, and relative speed between the point and the LIDAR system. A value of a property of an object in the point cloud is determined based on only three or fewer of the at least four dimensions. In some of embodiments, determining the value of the property of the object includes isolating multiple points in the point cloud data which have high value Doppler components. A moving object within the plurality of points is determined based on a cluster by azimuth and Doppler component values.

PROCESSING TEMPORAL SEGMENTS OF LASER CHIRPS AND EXAMPLES OF USE IN FMCW LIDAR METHODS AND APPARATUSES

Examples of FMCW laser radar systems and methods described herein may segment the processing of a broader bandwidth frequency chirp into multiple shorter-duration (e.g., lower bandwidth) frequency chirps. This segmentation may have the benefits in some examples of improving the measurement duty cycle and range resolution, and/or allowing for more flexible processing, and/or enabling improved detection of more distant objects. 1. A method comprising:producing an interference signal from a frequency-modulated continuous wave (FMCW) laser radar system, the interference signal corresponding to a laser chirp over a chirp bandwidth;processing multiple temporal segments of the interference signal, each of the multiple temporal segments corresponding to a respective segmented bandwidth, each of the respective segmented bandwidths being less than the chirp bandwidth; anddetermining a distance to at least a portion of an object based on the processing.2. The method of claim 1 , wherein producing the interference signal comprises:directing a transmit portion of a laser beam corresponding to the laser chirp toward the object; andcombining a reflected portion of the transmit portion of the laser beam with a local oscillator portion of the laser beam.3. The method of claim 1 , wherein said processing comprises combining results from processing the multiple temporal segments.4. The method of claim 3 , wherein said combining comprises averaging.5. The method of claim 4 , wherein said averaging comprises incoherent averaging.6. The method of claim 1 , wherein the interference signal comprises a first interference signal claim 1 , the first interference signal corresponding to a first laser chirp comprising a first set of multiple temporal segments claim 1 , the method further comprising producing a second interference signal from the frequency-modulated continuous wave (FMCW) laser radar system claim 1 , the second interference signal corresponding to a second laser chirp comprising ...

INJECTION LOCKED ON-CHIP LASER TO EXTERNAL ON-CHIP RESONATOR

Various technologies described herein pertain to injection locking on-chip laser(s) and external on-chip resonator(s). A system includes a first integrated circuit chip and a second integrated circuit chip. The first integrated circuit chip and the second integrated circuit chip are separate integrated circuit chips and can be optically coupled to each other. The first integrated circuit chip includes a laser configured to emit light via a first path and a second path. The second integrated circuit chip includes a resonator formed of an electrooptic material. The resonator can receive the light emitted by the laser of the first integrated circuit chip via the first path and return feedback light to the laser of the first integrated circuit chip via the first path. The feedback light can cause injection locking of the laser to the resonator to control the light emitted by the laser (e.g., via the first and second paths). 1. A system , comprising: 'a laser configured to emit light via a first path and a second path; and', 'a first integrated circuit chip, comprising 'a resonator formed of an electrooptic material, the resonator configured to receive the light emitted by the laser of the first integrated circuit chip via the first path and return feedback light to the laser of the first integrated circuit chip via the first path, wherein the feedback light causes injection locking of the laser to the resonator to control the light emitted by the laser via the second path.', 'a second integrated circuit chip, the second integrated circuit chip and the first integrated circuit chip being separate integrated circuit chips, the second integrated circuit chip being optically coupled with the first integrated circuit chip, the second integrated circuit chip comprising2. The system of claim 1 , the first integrated circuit chip further comprises a lidar optical engine claim 1 , the lidar optical engine comprises one or more lidar components claim 1 , wherein the light emitted ...

TIME OF FLIGHT RANGING SYSTEM USING MULTI-VALUED SIGNALS

A time of flight (TOF) ranging system includes multiple emitters, each emitting a signal whose intensity, amplitude or polarization is modulated by a corresponding delayed modulation signal. Each delayed modulation signal is a delayed version of a time varying multi-valued modulation signal, the amount of delay being determined by a spatial position of the emitter and direction of a target point on the target. The signal reflected by the target is correlated with the original modulation signal to generate an output having a peak representing the TOF to the target point. The same process is performed to detect other target points. Another TOF ranging system includes one emitter and multiple detectors; the signal from each detector is delayed in a similar manner and their sum is correlated with the original modulation signal to generate an output representing TOF. Yet another TOF ranging system includes multiple emitters and multiple detectors. 1. A time of flight ranging system comprising:a plurality of emitting devices forming an array;a signal generator configured to generate a time varying multi-valued modulation signal;a signal processing unit coupled to the signal generator to receive the time varying multi-valued modulation signal and configured to generate a plurality of delayed modulation signals, wherein each delayed modulation signal corresponds to one of the plurality of emitting devices and is the time varying multi-valued modulation signal delayed by a predetermined time delay, the predetermined time delay being determined by a spatial position of the corresponding emitting device in the array and a target direction which is a direction from a reference point of the array to a target point on a target being ranged;wherein each of the plurality of emitting devices is coupled to the signal processing unit to receive the corresponding delayed modulation signal, each emitting device being configured to emit a wave signal having modulated intensities or ...

OPTICAL RESONATOR WITH LOCALIZED ION-IMPLANTED VOIDS

A high Q whispering gallery mode resonator with ion-implanted voids is described. A resonator device includes a resonator disk formed of an electrooptic material. The resonator disk includes a top surface, a bottom surface substantially parallel to the top surface, and a side structure between the top surface and the bottom surface. The side structure includes an axial surface along a perimeter of the resonator disk, where a midplane passes through the axial surface dividing the axial surface into symmetrical halves. The whispering gallery mode resonator disk includes voids localized at a particular depth from the top surface. At least one of the voids localized at the particular depth from the top surface is located at an outer extremity towards the perimeter of the resonator disk. The resonator device can further include a first electrode on the top surface and a second electrode on the bottom surface. 1. A resonator device , comprising: a top surface;', 'a bottom surface substantially parallel to the top surface;', 'a side structure between the top surface and the bottom surface, the side structure comprises an axial surface along a perimeter of the whispering gallery mode resonator, wherein a midplane passes through the axial surface dividing the axial surface into symmetrical halves; and', 'voids localized within a particular depth range from the top surface, the particular depth range from the top surface being between the top surface and the midplane, the voids being bubbles formed within the electrooptic material, wherein at least one of the voids localized within the particular depth range from the top surface is located at an outer extremity towards the perimeter of the whispering gallery mode resonator;, 'a whispering gallery mode resonator formed of an electrooptic material, the whispering gallery mode resonator comprisinga first electrode on the top surface of the whispering gallery mode resonator; anda second electrode on the bottom surface of the ...

Light optical angle modulation measurement apparatus and measurement method

An apparatus and a method which enable, in optical angle modulation, measurement of laser light, to measure by a delayed self-heterodyne method, accurate measurement of a temporal waveform of optical angle modulation, without any influence by light intensity modulation, without necessity of for calibration, and without necessity for stabilizing an interferometer. In an optical angle modulation measurement apparatus using a delayed self-heterodyne method, a heterodyne interferometer that is fed with laser light to be measured; a photodetector that receives output light of the heterodyne interferometer and performs heterodyne detection of the output light to output a beat signal; using a phase demodulator that is configured to demodulate a phase of a beat signal; and a temporal waveform analyzer that is configured to obtain a temporal waveform of optical angle modulation, from the phase of the beat signal. In an optical angle modulation measurement method by a delayed self-heterodyne method, laser light to be measured, which is optical-angle modulated is input to a heterodyne interferometer, heterodyne detection of the output light is performed by a photodetector, and a temporal waveform of optical angle modulation is obtained by demodulating a phase of the beat signal.

LIDAR WITH DELAYED REFERENCE SIGNAL

Systems and methods described herein are directed to extending a range of operation of a remote imaging system including a Light Detection and Ranging (LIDAR) system. Example embodiments describe delaying a locally generated reference signal in time with respect to an outgoing LIDAR signal. By delaying the reference signal, the system can effectively increase a maximum range of target detection while maintaining the accuracy of target detection. In some embodiments, by delaying the reference signal, the system may be able to reduce the effects of phase noise and chirp non-linearities on the beat signal and effectively improve the signal-to-noise ratio. As such, the maximum range of operation of the system may be increased while maintaining highly accurate estimations of target depth and/or velocity. 1. A remote imaging system comprising: determine a delay time associated with an extended range of operation, wherein the extended range of operation comprises an extended maximum detection distance;', 'generate a delayed reference signal based on the determined delay time;', 'generate an outgoing LIDAR signal for scanning a target located within the maximum detection distance;', 'receive a LIDAR input signal associated with the target and the outgoing LIDAR signal; and', 'generate a beat signal based on the delayed reference signal and the received LIDAR input signal; and, 'at least one Light Detection and Ranging (LIDAR) chip configured toa computing device configured to receive the beat signal from the at least one LIDAR chip.2. The system of claim 1 , further comprising control circuitry configured to operate an optical switch.3. The system of claim 2 , wherein the optical switch is configured to select different optical delay lines.4. The system of claim 2 , wherein the optical switch is configured to select an optical delay line that corresponds to the determined delay time.5. The system of claim 1 , wherein the maximum detection distance is associated with at ...

LASER RADAR, AND LIGHT RECEIVING METHOD OF LASER RADAR

A laser radar device includes: a light source; a projection light scanner that scans one part of light split off from emission light of the light source, and that generates transmission light for radiating onto a target object; an image forming section that forms plural respective reception lights of the transmission light reflected by respective locations of the target object into an image on a single flat plane as plural image-formation points; an optical receiver that is disposed at the plural image-formation points, and that includes plural unit optical reception sections for mixing each of the plural reception lights together with a reference light and performing optical heterodyne detection; and a reference light scanner that scans or distributes another light split off from the emission light from the light source, and that generates the reference light for radiating onto each of plural of the unit optical reception sections. 1. A laser radar device comprising:a light source;a projection light scanner that scans one part of light split off from emission light of the light source, and that generates transmission light for radiating onto a target object;an image forming section that forms a plurality of respective reception lights, from the transmission light reflected by respective locations of the target object, into an image on a single flat plane as a plurality of image-formation points;an optical receiver including a plurality of unit optical reception sections that are disposed at the plurality of image-formation points, and that mix each of the plurality of reception lights together with a reference light and perform optical heterodyne detection; anda reference light scanner that scans or distributes another part of the light split off from the emission light of the light source, and that generates the reference light for radiating onto each of the plurality of unit optical reception sections, whereineach unit optical reception section includes an ...

MICROLENS ARRAY LIDAR SYSTEM

An integrated light detection and ranging (LiDAR) architecture can contain a focal plane transmitter array, and a focal plane coherent receiver for which the number of receiving elements is the same as the number of emitting elements. A microlens array may be used to achieve parity between the number of receiver and transmitter elements. The integrated LiDAR transmitter can contain an optical frequency chirp generator and a focal plane optical beam scanner with integrated driving electronics. The integrated LiDAR receiver architecture can be implemented with per-pixel coherent detection and amplification. 1. A method for generating ranging data using a light detection and ranging system comprising:generating, using a transmitter array of a photonic integrated circuit, light from one or more light sources in the light detection and ranging system;directing the light from one or more couplers to one or more external objects, the light being directed though a microlens array that outputs to a lens that directs the light towards the one or external objects;receiving light using a receiver array of the light detection and ranging system; andgenerating, using an electronic integrated circuit of the light detection and ranging system, the ranging data from reflected light that is reflected from the one or more external objects.2. The method of claim 1 , wherein the light generated by the transmitter array is frequency modulated light.3. The method of claim 2 , wherein the frequency modulated light is frequency modulated continuous wave (FMCW) light having a changing optical frequency.4. The method of claim 1 , wherein the light directed into the microlens array is split into a plurality of sub-beams of light that are directed to the lens and to the one or more external objects.5. The method of claim 1 , wherein the microlens array has a plurality of sub-lenses that generate a plurality of sub-beams of light.6. The method of claim 5 , wherein a first quantity of the ...

Lidar pixel with active polarization control

A light detection and ranging (LIDAR) pixel includes a polarization controller, a grating coupler, and an optical mixer. The polarization controller includes a phase shifter that sets a phase of light in a first arm of the polarization controller and a second arm of the polarization controller.

System and Method for Tracking Objects Using Lidar and Video Measurements

A system uses range and Doppler velocity measurements from a lidar system and images from a video system to estimate a six degree-of-freedom trajectory of a target. The system estimates this trajectory in two stages: a first stage in which the range and Doppler measurements from the lidar system along with various feature measurements obtained from the images from the video system are used to estimate first stage motion aspects of the target (i.e., the trajectory of the target); and a second stage in which the images from the video system and the first stage motion aspects of the target are used to estimate second stage motion aspects of the target. Once the second stage motion aspects of the target are estimated, a three-dimensional image of the target may be generated. 1. A system for tracking a target from lidar measurements and video images , the system comprising:a lidar subsystem configured to direct a beam toward the target and to provide a range measurement and a Doppler velocity measurement for each of a plurality of points on the target;a video subsystem configured to capture a plurality of two-dimensional images of the target; and receive, from the lidar subsystem, the range measurement and the Doppler velocity measurement for each of the plurality of points on the target,', 'receive, from the video subsystem, the plurality of images of the target,', {'sub': z', 'x', 'y, 'sup': 'trans', 'estimate a translational velocity component vand angular velocity components ωand vfor each of the plurality of points on the target from the range measurements and the Doppler velocity measurements from the lidar subsystem,'}, {'sub': x', 'y', 'z', 'z', 'x', 'y, 'sup': trans', 'trans', 'trans, 'estimate translational velocity components vand vand the angular velocity component ωfor each of the plurality of points on the target from two-dimensional position and velocity measurements of at least one feature of the target obtained from the plurality of images of the target ...

SYSTEM AND METHOD FOR REFINING COORDINATE-BASED THREE-DIMENSIONAL IMAGES OBTAINED FROM A THREE-DIMENSIONAL MEASUREMENT SYSTEM

A system uses range and Doppler velocity measurements from a lidar system and images from a video system to estimate a six degree-of-freedom trajectory of a target and generate a three-dimensional image of the target. The system may refine the three-dimensional image by reducing the stochastic components in the transformation parameters between video frame times. 1. A system for refining 3D images , the system comprising:a lidar subsystem configured to direct at least two beams toward the target, generate a first set of line scan 3D measurements for a plurality of points on the target for a first beam of the at least two beams, and generate a second set of overscan 3D measurements for the plurality of points on the target for a second beam of the at least two beams;a video subsystem configured to provide a set of the video frames of the target; and receive, from the lidar subsystem, the line scan 3D measurements and the set of overscan 3D measurements,', 'receive, from the video subsystem, the a set of the video frames of the target,', 'determine, at each frame time, a plurality of Δz offsets between pre over-scan measurements and the line scan 3D measurements and post over-scan measurements and the line scan 3D measurements, and', 'adjust a plurality of transformation parameters based on a least square optimization., 'a processor configured to2. A system for refining 3D images , the system comprising:a lidar subsystem configured to direct at least two beams toward the target, and generate a plurality of 3D measurements for a plurality of points on the target for each beam of the at least two beams;a video subsystem configured to provide the set of the video frames of the target; and receive, from the lidar subsystem, the plurality of 3D measurements,', 'receive, from the video subsystem, the set of the video frames of the target,', 'transform each of the set of video frames to a next frame time and a previous frame time to generate a set of transformed video frames ...

DIGITIZATION SYSTEMS AND TECHNIQUES AND EXAMPLES OF USE IN FMCW LIDAR METHODS AND APPARATUSES

Examples are provided that use multiple analog-to-digital converters (ADCs) to disambiguate FMCW ladar range returns from one or more targets that may be greater than the Nyquist frequencies of one or more of the ADCs. Examples are also provided that use a first and a second laser FMCW return signal (e.g., reflected beam) in combination with two or more ADCs to disambiguate one or more target ranges (e.g., distances to one or more objects). 1. A method comprising:providing an interference signal from a frequency-modulated continuous-wave (FMCW) laser radar system, the interference signal based in part on a laser beam reflected from an object;digitizing the interference signal using a digitizer having a Nyquist frequency lower than an actual beat frequency of the interference signal to produce a digitized signal, the digitized signal consistent with multiple candidate beat frequencies;processing the digitized signal to select one of the multiple candidate beat frequencies corresponding to the actual beat frequency; anddetermining a distance to at least a portion of the object based on the beat frequency.2. The method of claim 1 , wherein the digitizer comprises a first analog to digital converter (ADC) claim 1 , and wherein the digitized signal comprises a first digitized signal corresponding to an output of the first ADC and wherein the first digitized signal is consistent with first multiple beat frequencies claim 1 , the method further comprising:digitizing the interference signal using a second ADC having a second Nyquist frequency to produce a second digitized signal, the second digitized signal consistent with a second set of multiple candidate beat frequencies; andwherein processing comprises selecting a matching one from the first and second set of multiple candidate beat frequencies.3. The method of claim 1 , further comprising providing at least another interference signal claim 1 , the at least another interference signal based in part on another laser ...

DISTANCE MEASURING SENSOR AND DISTANCE MEASURING METHOD

A TOF-system distance measuring sensor comprises: a light source unit that radiates light to a target as the irradiation light, the light being subjected to primary modulation so that the distance to the target can be measured and being subjected to secondary modulation so that influences of disturbance light are reduced; and a light receiving unit that receives the reflection light subjected to the secondary modulation and that subjects the reflection light subjected to the secondary modulation to secondary demodulation so that influences of disturbance light are reduced. 1. A TOF-system distance measuring sensor that measures a distance to a target by measuring a time from when a light source unit radiates irradiation light to the target until a light receiving unit receives reflection light reflected by the target , the distance measuring sensor comprising:a light source unit that radiates light to the target as the irradiation light, the light being subjected to primary modulation so that the distance to the target can be measured and being subjected to secondary modulation so that influences of disturbance light are reduced; anda light receiving unit that receives the reflection light subjected to the secondary modulation and that subjects the reflection light subjected to the secondary modulation to secondary demodulation so that influences of disturbance light are reduced.2. The distance measuring sensor according to claim 1 , wherein the light source subjects at least one of polarization claim 1 , an amplitude claim 1 , a frequency claim 1 , and a phase of the light to the primary modulation so that the distance to the target can be measured.3. The distance measuring sensor according to claim 1 , wherein claim 1 , based on a direct spreading system using a PN code in an m-sequence claim 1 , the light source unit subjects the light to the secondary modulation so that the influences of the disturbance light are reduced.4. The distance measuring sensor ...

PORTABLE PANORAMIC LASER MAPPING AND/OR PROJECTION SYSTEM

Techniques are described herein that are capable of forming a depth map and/or projecting an image onto object(s) based on the depth map. A depth map is a three-dimensional representation of an environment. Forming the depth map may utilize a progressive resolution refinement technique. For example, locating information may be determined in accordance with the progressive resolution refinement technique in response to performing a scan of a current point over a field of view. The current point is a point, selected from a plurality of points (e.g., a grid of points) in the field of view, to which a detection beam of light is directed at a respective time as the scan is performed over the field of view. In accordance with this example, the locating information may be coordinated with the scan to form the depth map. 1. A method of performing progressive resolution refinement , the method comprising:performing a first measurement with a relatively low resolution using modulated coherent light;processing the first measurement electrically to determine low-resolution locating information, the low-resolution locating information including a relatively low resolution estimate of a distance between a reference location and a current point;performing a second measurement with a relatively high resolution; andprocessing the second measurement electrically using the low-resolution locating information to enable the processing of the second measurement to determine high-resolution locating information, the high-resolution locating information including a relatively high resolution estimate of the distance between the reference location and the current point.2. The method of claim 1 , further comprising:modulating coherent light in frequency to provide the modulated coherent light;splitting the modulated coherent light into a reference beam and a detection beam; andreducing a frequency range over which a beat frequency of a beat signal is to be searched by more than a factor of ...

Light conveyance in a lidar system with a monocentric lens

A coherent lidar system includes a light source to output a continuous wave, and a modulator to modulate a frequency of the continuous wave and provide a frequency modulated continuous wave (FMCW) signal. The system also includes a ball lens to obtain a receive beam resulting from a reflection of an output signal, obtained from the FMCW signal, by a target, and a light conveyer to convey the receive beam obtained by the ball lens to a beam steering device that directs the receive beam to a receive path of the system.

Navigation system for GPS denied environments

Methods and apparatus for providing self-contained guidance, navigation, and control (GN&C) functions for a vehicle moving through an environment on or near the ground, in the air or in space without externally provided information are disclosed. More particularly, one embodiment of the present invention includes a Heading Sensor ( 36 ), an Absolute Location Sensor ( 38 ), a timer ( 40 ), a Range Doppler Processor ( 42 ), a Navigation Reference Sensor ( 44 ), an Area Range and a Velocity Sensor ( 46 ) which provide enhanced navigation information about a universal reference frame ( 22 ) and one or more targets ( 20 ).

Ranging module

In a ranging module, a first calculator calculates a distance from a processed signal corresponding to a current pixel. A determiner determines whether the distance calculated by the first calculator differs from a preset limit distance. A re-extractor is configured to, in response to the determiner determining that the distance differs from the preset limit distance, extract pieces of data of processing sections each corresponding to a sweep time of a transmission wave from a time-series of the processed signals saved in a data storage corresponding from a pixel previous to the current pixel in a scanning direction of a scanner to the current pixel while shifting the processing sections one after the other by a time period shorter than the sweep time. A second calculator calculates the distance from the data of each processing section extracted by the re-extractor.

LIGHT WAVE DISTANCE METER

A light wave distance meter according to the present invention includes: a light-emitting element that emits a distance measurement light; a light-receiving element that outputs a light-receiving signal; a frequency conversion unit that includes a bandpass filter; an arithmetic control unit that computes a distance value to a measurement object; a signal generator that generates a signal having a predetermined frequency; a waveform conversion unit that generates a waveform conversion signal; pulse generators that generate pulse signals by pulsating the signal having a predetermined frequency so as to have a waveform profile of a signal constituted of desired frequency components on the basis of the signal output from the signal generator and the waveform conversion signal output from the waveform conversion unit; and a drive unit that emits the distance measurement light based on the pulse signals. 1. A light wave distance meter that irradiates a measurement object with a distance measurement light , and measures a distance to the measurement object based on a reflected distance measurement light that is the distance measurement light reflected by the measurement object , comprising:a light-emitting element that emits the distance measurement light;a light-receiving element that receives the reflected distance measurement light and outputs a light-receiving signal in accordance with the reflected distance measurement light;a frequency conversion unit that includes a bandpass filter that allows a specific frequency band to pass, out of the light-receiving signal output from the light-receiving element;an arithmetic control unit that executes arithmetic processing to determine a distance value to the measurement object based on the signal output from the frequency conversion unit;a signal generator that generates a signal having a predetermined frequency;a waveform conversion unit that generates a waveform conversion signal that is constituted of desired frequency ...

Method for processing a signal from a coherent lidar in order to reduce noise and related lidar system

A method for processing a signal from a coherent lidar includes a coherent source, the method comprising steps consisting of: generating a first beat signal and a second beat signal, using respectively a first detection assembly and a second detection assembly for a plurality of n time intervals, determining n respective values of spectral density using a transform in the frequency domain of the cross-correlation between the first and second beat signals, determining a mean value of the spectral density using said n values of spectral density, determining a piece of location information on the target using the mean value of said spectral density.

Lidar apparatus for vehicles and vehicle having the same

A light detection and ranging (lidar) apparatus for a vehicle may include: a transmission unit configured to output transmission light; a reception unit configured to receive reflection light that results from the transmission light being reflected by an object; and at least one processor. The at least one processor may be configured to: based on a driving state of the vehicle, adjust an angle of beam steering of the transmission light.

Compressive scanning lidar

A method for increasing resolution of an image formed of received light from an illuminated spot includes measuring a y vector for measurement kernels A 1 to A M , where M is a number of the measurement kernels, measuring the y vector including programming a programmable N-pixel micromirror or mask located in a return path of a received reflected scene spot with a jth measurement kernel A j of the measurement kernels A 1 to A M , measuring y, wherein y is an inner product of a scene reflectivity f(α,β) with the measurement kernel A j for each range bin r i , wherein α and β are azimuth and elevation angles, respectively, repeating programming the programmable N-pixel micromirror or mask and measuring y for each measurement kernel A 1 to A M , and forming a reconstructed image using the measured y vector, wherein forming the reconstructed image includes using compressive sensing or Moore-Penrose reconstruction.