Abstract: A light detection and ranging (LIDAR) system, includes a memory, and a processor, operatively coupled to the memory, to identify an obstruction of the LIDAR system based on a comparison of a frequency of an energy peak generated from a return signal to a threshold frequency and mitigate the obstruction.

Abstract: A light detection and ranging (LIDAR) technique that includes dividing the field of view into a grid including a plurality of cells. The technique also includes transmitting an optical beam and generating a baseband signal based on a returned optical beam. The baseband signal includes a plurality of peaks corresponding with up-chirps and down-chirps in the transmitted signal. The technique also includes generating a negative image of the second peak to generate a third peak, computing, using the first peak and the second peak, a first point having a first velocity and a first location within a first cell, and computing, using the first peak and the third peak, a second point having a second velocity and a second location within a second cell. The technique also includes determining whether to accept the first point or the second point for inclusion in a point cloud.

Abstract: 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.

Abstract: A method transmits a first optical beam towards targets within a field of view (FOV). The first optical beam is modulated at a first chirp rate for a first set of scan lines that correspond to a first distance of the targets. The method identifies conditions based on the FOV to calculate a second chirp rate, and generates a scan pattern by transmitting a second optical beam towards the targets within the FOV. The second optical beam is modulated at the second chirp rate for a second set of scan lines that corresponds to a second distance of the one or more targets. The method generates, based on the first and second optical beams, the point cloud that includes multiple data points related to the target in which some of the data points are related to a first target and other data points are related to a second target.

Abstract: A light detection and ranging (LIDAR) system to transmit an optical beam toward a target and receive a returned optical beam. The optical beam includes an up-chirp frequency and a down-chirp frequency, and is modulated to have phase non-linearities. The LIDAR system generates a baseband signal from the returned optical beam, which includes a plurality of peaks corresponding with the up-chirp frequency and the down-chirp frequency. The LIDAR system identifies a first true peak in the baseband signal, and identifies a second true peak in the baseband signal based, at least in part, on a spectral shape of the second true peak caused by the phase non-linearities. The LIDAR system is to determine the location of the target using the first true peak and the second true peak.

Abstract: A method transmits a first optical beam towards targets within a field of view (FOV). The first optical beam is modulated at a first chirp rate for a first set of scan lines that correspond to a first distance of the targets. The method identifies conditions based on the FOV to calculate a second chirp rate, and generates a scan pattern by transmitting a second optical beam towards the targets within the FOV. The second optical beam is modulated at the second chirp rate for a second set of scan lines that corresponds to a second distance of the one or more targets. The method generates, based on the first and second optical beams, the point cloud that includes multiple data points related to the target in which some of the data points are related to a first target and other data points are related to a second target.

Abstract: The LiDAR system includes a coherent receiver disposed in a reference path. The coherent receiver includes a 90° optical hybrid to receive a portion of an optical beam along the reference path and a local oscillator (LO) signal to generate multiple output signals. The coherent receiver includes a first photodetector to receive a first and a second output signal to generate a first mixed signal, and a second photodetector to receive a third and a fourth output signal to generate a second mixed signal. The LiDAR system further includes a processor to combine the first mixed signal and the second mixed signal to generate a combined reference signal. A negative image of a reference beat frequency signal produced by the optical beam and the LO signal is suppressed to estimate a phase noise of the optical source to determine at least one of range or velocity information of the target.

Abstract: 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.

Abstract: A frequency modulated continuous wave (FMCW) light detection and ranging (LIDAR) system includes a processor and a memory. The memory stores instructions that, when executed by the processor, cause the system to: receive samples of a range-dependent time domain baseband signal; assemble the samples into sample blocks in the time domain; convert the sample blocks from the time domain to the frequency domain; generate subbands in the frequency domain from converted sample blocks; classify the subbands into a plurality of subband types based on subband typing criteria; select subband processing parameters for each of the subbands based on respective ones of the plurality of subband types; and process each of the subbands using the selected subband processing parameters for the subband.

Abstract: A method to compensate for phase impairments in a light detection and ranging (LIDAR) system includes estimating one or more phase impairments in the LIDAR system using a digitally-sampled reference signal to produce one or more estimated phase impairments and performing one or more corrections on one or more phase impairments in a digitally-sampled target signal based on the one or more estimated phase impairments.

Abstract: Techniques for cascade filtering of a set of points of interest (POIs) in a light detection and ranging (LiDAR) system is described. The method includes performing a series of cascaded filtering of a set of points of interest (POIs) on a first point cloud. The method includes calculating, for each POI of the set of POIs, at least a first metric for a first set of neighborhood points to make a decision with respect to a subset of the set of POIs for transmission to a second point cloud. The method also includes extracting at least one of range or velocity information based on the second point cloud based on the decision.

Abstract: A method to select multiple returns in a light detection and ranging (LIDAR) system includes thresholding a frequency domain waveform to identify a number of peaks above a threshold level. After thresholding, a primary peak selection is applied to identify a primary peak. After identifying a primary peak, a secondary peak selection is applied to a portion of the frequency domain waveform outside a guard-band area to identify a secondary peak.

Abstract: A light detection and ranging (LIDAR) system includes an automatic gain control (AGC) unit to reduce the dynamic range, reducing processing power and saving circuit area and cost. The system detects a return beam of a light signal transmitted to a target, having a first dynamic range in a time domain. An analog to digital converter (ADC) generates a digital signal based on the return beam. A processor can perform time domain processing on the digital signal, convert the digital signal from the time domain to a frequency domain, and perform frequency domain processing on the digital signal in the frequency domain. The AGC unit can measure a power of the return beam, and apply variable gain in the frequency domain to reduce a dynamic range of the return beam to a second dynamic range lower than the first dynamic range.

Abstract: A method transmits a predetermined signal through a first channel that includes a first digital circuit to produce a first result. The first channel is a functional channel in the FMCW LIDAR system. The method retrieves a second result that is based on the predetermined signal, and determines whether the first result and the second result are nonequivalent. The method then invokes a fault signal in response to determining that the first result and the second result are nonequivalent.

Abstract: A set of POIs of a point cloud are received at a first filter, where each POI of the set of POIs comprises one or more points. Each POI of the set of POIs is filtered. A set of neighborhood points of a POI is selected. A metric for the set of neighborhood points is computed based on a property of the set of neighborhood points and the POI, wherein the property comprises a velocity. Based on the metric, whether to accept the POI, modify the POI, reject the POI, or transmit the POI to a second filter, to extract at least one of range or velocity information related to the target is determined. Provided the POI is not accepted, modified, or rejected, the POI is transmitted to the second filter to determine whether to accept, modify, or reject the POI to extract the at least one of range or velocity information related to the target.

Abstract: A method generates first points based on a first scan of an environment that includes one or more moving objects. The method transforms the first points into a first static frame, which includes removing one or more of the first points corresponding to the one or more moving objects. The method generates second points based on a second scan of the environment that includes the one or more moving objects. The method transforms the second points into a second static frame, which includes removing one or more of the second points corresponding to the one or more moving objects. The method combines the first static frame and the second static frame into an accumulated static frame, which has an increase in resolution compared with the first static frame. The method then loads the accumulated static frame into a point cloud.

Abstract: A light detection and ranging (LIDAR) system transmits, towards a target, a set of chirp signals. The LIDAR system receives from the target, a set of adjusted chirp signals. The LIDAR system then determines, based on the set of adjusted chirp signals, a degree of ghosting mitigation to compensate for a ghost target appearing in a point cloud at a location where no real target exists.

Abstract: 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.

Abstract: A light detection and ranging (LIDAR) technique that includes dividing the field of view into a grid including a plurality of cells. The technique also includes generating a baseband signal based on a returned optical beam. The baseband signal includes a plurality of peaks corresponding with up-chirps and down-chirps in the transmitted signal. A plurality of points are computed based on the peaks. Each point includes information describing a range and a velocity and corresponds to a respective cell. A point confidence score is computed for each point, and a cell confidence score is computed for each cell based on the point confidence scores of the points within the cell. Each point can be accepted or rejected for inclusion in a point cloud based on the point confidence score for the point and the cell confidence scores for the plurality of cells.

Abstract: A method including receiving, responsive to a transmission of a plurality of optical beams into an environment including a target, a plurality of returned optical beams associated with the target. The method includes generating a plurality of points from the plurality of returned optical beams, wherein each one of the plurality of points respectively corresponds to one of the plurality of returned optical beams; selecting a first point from the plurality of points and a second point from the plurality of points. The method includes identifying, by a processor, an orientation of the first point relative to the FMCW LIDAR system based on the second point from the plurality of points. The method includes computing an orientation of the target relative to the FMCW LIDAR system based on the orientation of the first point; and generating a point cloud based on the orientation of the target.