Abstract: A system includes an acoustic source localization system configured to detect an acoustic signal and determine its location relative to the system. The system also includes a lidar system and a controller. The lidar system includes a light source to emit pulses of light, a scanner to scan a field of regard of the lidar system according to a scan pattern, and a detector to detect light from some of the light pulses scattered by remote targets to generate respective pixels in a point cloud representing objects within the field of regard. The controller configured to receive, from the acoustic source localization system, an indication of the determined location, identify a region of interest within the field of regard that includes the determined location of the source, and cause the lidar system to obtain more data within the region of interest relative to other regions within the field of regard.

Abstract: A lidar system includes a transmitter that encodes successive transmit pulses with different pulse characteristics and a receiver that detects the pulse characteristics of each received (scattered or reflected) pulse and that distinguishes between the received pulses based on the detected pulse characteristics. The lidar system thus resolves range ambiguities by encoding pulses of scan positions in the same or different scan periods to have different pulse characteristics, such as different pulse widths or different pulse envelope shapes. The receiver includes a pulse decoder configured to detect the relevant pulse characteristics of the received pulse and a resolver that determines if the pulse characteristics of the received pulse matches the pulse characteristics of the current scan position or that of a previous scan position.

Abstract: A multispectral lidar system includes a laser configured to emit a pulse of light including a first wavelength, scanner configured to direct the emitted pulse of light in accordance with a scan pattern, a receiver including a first detector and a second detector, and a controller. The first detector is configured to detect the emitted pulse of light scattered by a remote target, and the second detector is configured to detect light scattered or emitted by the remote target and including a second wavelength. The scanner provides, at any point in time, a fixed spatial relationship between the fields of view over which the light with the first wavelength and the second wavelength is received. A controller can determine a distance to the remote target and use this distance to modify a measurement of the property of the remote target based on the light detected by the second detector.

Abstract: To detect an atmospheric condition at the current location of a lidar system, a receiver in the lidar system detects a return light pulse scattered by a target and analyzes the characteristics of the return light pulse. The characteristics of the return light pulse include a rise time, a fall time, a duration, a peak power, an amount of energy, etc. When the rise time, fall time, and/or duration exceed respective thresholds, the lidar system detects the atmospheric condition such as fog, sleet, snow, rain, dust, smog, exhaust, or insects. In response to detecting the atmospheric condition, the lidar system adjusts the characteristics of subsequent pulses to compensate for attenuation or distortion of return light pulses due to the atmospheric condition. For example, the lidar system adjusts the peak power, pulse energy, pulse duration, inter-pulse-train spacing, number of pulses, or any other suitable characteristic.

Abstract: A method for calibrating lidar systems operating in vehicles includes detecting a triggering event, causing the lidar system to not emit light during a calibration period, determining an amount of noise measured by the lidar system during the calibration period, generating a noise level metric based on the amount of noise detected during the calibration period, and adjusting subsequent readings of the lidar system using the noise level metric. The adjusting includes measuring energy levels of return light pulses emitted from the lidar system and scattered by targets and offsetting the measured energy levels by the noise level metric.

Abstract: A lidar system comprises a light source configured to emit pulses of light, a scanner configured to direct the pulses of light along a scan direction, where each of the pulses of light illuminates a respective field of view of the light source, and a receiver configured to detect the pulses of light scattered by remote targets. The receiver includes a low-gain detector associated with a low gain and a high-gain detector associated with a high gain. The low-gain detector is positioned so that a first scattered pulse of light that returns from a first target, located closer to the receiver than a second target, is detected primarily by the low-gain detector, and a second scattered pulse of light that returns from the second target is detected primarily by the high-gain detector.

Abstract: To detect light from light pulses at the operating wavelength of a light source in a lidar system, a thin-film notch filter is directly deposited on a photodetector or a lens via vacuum deposition or monolithic epoxy. The thin-film notch filter may include an anti-reflective coating such as a pattern-coated dichroic filter having an optical transmission of 90% or greater at in-band wavelengths and less than 5% at out-of-band wavelengths. To deposit the filter onto the photodetector without disrupting electronic connections between the photodetector and an application-specific integrated circuit, the area surrounding the electrodes on the photodetector is kept open using photolithography.

Abstract: A lidar system includes a light source configured to emit light pulses and a receiver configured to detect light from some of the light pulses scattered by remote targets. The receiver includes an avalanche photodiode operating in the linear mode for detecting the light pulses. To prevent damage to the linear mode avalanche photodiode a quench circuit is coupled to the avalanche photodiode, where the quench circuit reduces a bias voltage applied to the avalanche photodiode, when an avalanche event occurs at the avalanche photodiode.

Abstract: A detector system within a lidar receiver is configured to compensate for range walk error by detecting both the rising edge and the falling edge of a received light pulse as the envelope of the received light pulse passes through a particular detection (magnitude) threshold. Detection circuitry within the detector system then determines the center of the received light pulse as the point equidistant in time between the detected rising and falling edges of the received light pulse, and uses the time associated with the center of the received light pulse to determine the range to the target from which the scattered light pulse was received.

Abstract: A light source includes a laser configured to emit a ranging pulse including a sequence of fast pulses. A lidar system uses one or more properties of the sequence of fast pulses to determine a signature of the ranging pulse. A receiver includes a detector element configured to detect a light signal and a signature detection circuitry configured to determine whether the detected light signal corresponds to the signature of the emitted ranging pulse. The lidar system is configured to generate a pixel value based on the detected light signal if the detected light signal corresponds to the signature of the emitted ranging pulse.

Abstract: A lidar system includes a lighting module configured to (i) select a wavelength from among a plurality of wavelength values, for a particular time period, and (ii) emit light at the selected wavelength. The lighting module emits light at different wavelengths during at least two adjacent periods of time. The lidar system further includes a scanner configured to direct the pulse of light to illuminate a respective region within a field of regard of the lidar system and a receiver module configured to (i) receive a light signal and (ii) determine whether the received light signal includes the light emitted by the lighting module and scattered by a remote target, based at least in part on the wavelength selected by the lighting module.

Abstract: A lidar system with a pulsed laser diode to produce a plurality of optical seed pulses of light at one or more operating wavelengths between approximately 1400 nm and approximately 1600 nm. The lidar system may also include one or more optical amplifiers to amplify the optical seed pulses to produce a plurality of output optical pulses. Each optical amplifier may produce an amount of amplified spontaneous emission (ASE), and the output optical pulses may have characteristics comprising: a pulse repetition frequency of less than or equal to 100 MHz; a pulse duration of less than or equal to 20 nanoseconds; and a duty cycle of less than or equal to 1%. The lidar system may also include one or more optical filters to attenuate the ASE and a receiver to detect at least a portion of the output optical pulses scattered by a target located a distance.

Abstract: A lidar system operates as an active short-wave infrared (SWIR) camera system to determine a four-dimensional image at each point in a two-dimensional field of regard. The camera system includes a short-wave infrared spectrum scanner that transmits a pulse of light at a particular position or coordinate in a two-dimensional field of regard and a receiver that detects return pulses scattered from a target in the field of regard coincident with the particular position. The receiver includes a detector that detects the returned pulse, a range determination unit that determines, based on the timing of the returned pulse, a distance to the target at the particular position, and an intensity measurement unit that determines the magnitude, amplitude, or intensity of the returned pulse, which information provides an indication of the relative, or in some cases, absolute reflectivity of the target at the particular point in the field of regard.

Abstract: A lidar system includes a lighting module configured to (i) select a wavelength from among a plurality of wavelength values, for a particular time period, and (ii) emit light at the selected wavelength. The lighting module emits light at different wavelengths during at least two adjacent periods of time. The lidar system further includes a scanner configured to direct the pulse of light to illuminate a respective region within a field of regard of the lidar system and a receiver module configured to (i) receive a light signal and (ii) determine whether the received light signal includes the light emitted by the lighting module and scattered by a remote target, based at least in part on the wavelength selected by the lighting module.

Abstract: A lidar system with a pulsed laser diode to produce a plurality of optical seed pulses of light at one or more operating wavelengths between approximately 1400 nm and approximately 1600 nm. The lidar system may also include one or more optical amplifiers to amplify the optical seed pulses to produce a plurality of output optical pulses. Each optical amplifier may produce an amount of amplified spontaneous emission (ASE), and the output optical pulses may have characteristics comprising: a pulse repetition frequency of less than or equal to 100 MHz; a pulse duration of less than or equal to 20 nanoseconds; and a duty cycle of less than or equal to 1%. The lidar system may also include one or more optical filters to attenuate the ASE and a receiver to detect at least a portion of the output optical pulses scattered by a target located a distance.

Abstract: A lidar system with a light source to emit a pulse of light and a receiver to detect a return pulse of light. The receiver can include a first channel to receive a first portion of the return pulse and produce a first digital output signal, and a second channel to receive a second portion of the return pulse and produce a second digital output signal. The receiver can include a logic circuit to produce an output electrical-edge signal in response to receiving the digital output signals. The receiver can also include a time-to-digital converter to determine a time interval based on an emission time of the pulse of light and based on the electrical-edge signal. The lidar system can also include a processor to determine a distance to a target based at least in part on the time interval.

Abstract: A lidar system with a light source to emit a pulse of light and a receiver to detect a return pulse of light. The receiver can include a first channel to receive a first portion of the return pulse and produce a first digital output signal, and a second channel to receive a second portion of the return pulse and produce a second digital output signal. The receiver can include a logic circuit to produce an output electrical-edge signal in response to receiving the digital output signals. The receiver can also include a time-to-digital converter to determine a time interval based on an emission time of the pulse of light and based on the electrical-edge signal. The lidar system can also include a processor to determine a distance to a target based at least in part on the time interval.

Abstract: A lidar system comprising with a light source, an optical link, and a sensor head. The light source can include a seed laser to produce pulses of light and an optical preamplifier to amplify the pulses of light. The optical link can convey amplified pulses of light to the sensor head remotely located from the light source. The sensor head can include an optical booster amplifier, a scanner to scan amplified output pulses of light across a field of regard, and a receiver to detect pulses of light scattered by a target located a distance from the sensor head.

Abstract: A lidar system with a pulsed laser diode configured to produce an optical seed pulse of light at an operating wavelength between approximately 1400 nm and approximately 1600 nm. The lidar system may also include an optical amplifier configured to amplify the optical seed pulse to produce an eye-safe output optical pulse that is emitted into a field of view. The optical amplifier may produce an amount of amplified spontaneous emission (ASE) associated with the output optical pulse. The lidar system may include an optical filter configured to filter the output optical pulse to reduce the associated ASE. The lidar system may also include a receiver configured to detect at least a portion of the output optical pulse reflected or scattered from the field of view.

Abstract: A lidar system having a light source to emit an output beam and an overlap mirror having a reflecting surface with an aperture through which the output beam passes. The lidar system may include mirrors driven by a galvanometer scanner, a resonant scanner, a microelectromechanical systems device, or a voice coil motor. The mirrors may direct the output beam toward a light source field of view (FOV) and may move the light source FOV to different locations within a field of regard. The mirrors may receive reflected portions of the output beam as an input beam and direct the input beam toward the reflecting surface of the overlap mirror. The lidar system may include a receiver to receive the input beam from the reflecting surface of the overlap mirror. The receiver may have a receiver FOV that moves synchronously with, and at least partially overlaps, the light source FOV.