G01S7/493

LIGHT DETECTION APPARATUS

In a light detection device, a circuit substrate includes a plurality of signal processing units which process a detection signal output from a corresponding pixel. Light-receiving regions of a plurality of avalanche photodiodes are two-dimensionally arranged for every pixel. In each of the signal processing units, a timing measurement unit measures timing at which light is incident on a corresponding pixel, based on the detection signal. An energy measurement unit measures energy of light incident on a corresponding pixel, based on the detection signal. A storage unit stores a measurement result in the timing measurement unit and the energy measurement unit. A light detection region where a plurality of the pixels are provided and a signal processing region where a plurality of the signal processing units are provided overlap each other at least at a part.

MEASUREMENT SYSTEM, MEASUREMENT METHOD, AND NON TRANSITORY COMPUTER READABLE STORAGE MEDIUM
20230033127 · 2023-02-02 ·

A measurement system determining a correspondence between detection signals regarding distance and relative speed of multiple targets includes: a first result acquisition unit performing FFT processing on a signal generated based on both of an in-phase component and an orthogonal component of the reception light, and acquiring, as a first result, a peak frequency regarding the distance and a peak frequency regarding the relative speed; a second result acquisition unit acquiring, as a second result, a peak frequency detected by performing FFT processing on at least one of the in-phase component signal and the orthogonal component signal; and a combination determination unit determining, as a third result, a combination of correspondence between the distance and the relative speed based on both of the first result and the second result.

Light detection and ranging receiver with avalanche photodiodes

A light detection and ranging (lidar) receiver may include a first photodiode, a first amplifier connected to the first photodiode, and a first analog-to-digital converter (ADC) connected to an output of the first amplifier. The lidar receiver may include a second photodiode, a second amplifier connected to the second photodiode, and a second ADC connected to the second amplifier. The lidar may include a processor connected to an output of the first ADC and an output of the second ADC and a direct-current-to-direct-current converter connected to an output of the processor and to the first photodiode and the second photodiode. The processor may determine, based on the output of the first ADC and the output of the second ADC, a first bias to apply to the first photodiode and a second bias to apply to the second photodiode.

Light detection and ranging receiver with avalanche photodiodes

A light detection and ranging (lidar) receiver may include a first photodiode, a first amplifier connected to the first photodiode, and a first analog-to-digital converter (ADC) connected to an output of the first amplifier. The lidar receiver may include a second photodiode, a second amplifier connected to the second photodiode, and a second ADC connected to the second amplifier. The lidar may include a processor connected to an output of the first ADC and an output of the second ADC and a direct-current-to-direct-current converter connected to an output of the processor and to the first photodiode and the second photodiode. The processor may determine, based on the output of the first ADC and the output of the second ADC, a first bias to apply to the first photodiode and a second bias to apply to the second photodiode.

TECHNIQUES FOR GHOSTING MITIGATION IN COHERENT LIDAR SYSTEMS USING IN-PHASE/QUADRATURE PHASE (IQ) PROCESSING

A light detection and ranging (LIDAR) system to transmit optical beams including at least up-chirp frequency and at least one down-chirp frequency toward targets in a field of view of the LIDAR system and receive returned signals of the up-chirp and the down-chirp as reflected from the targets. The LIDAR system may determine multiple frequency peaks associated with the target based on the returned signals. Upon determining that at least one of the multiple frequency peaks is within one or more sets of frequency ranges, the LIDAR system may combine an in-phase signal and a quadrature signal of the returned signals to generate a complex signal that enables determining whether the at least one of the multiple frequency peaks is associated with ghosting. Upon determining to be free from ghosting, the LIDAR system determines one or more of the target location, a target velocity, and a target reflectivity.

LIDAR SYSTEM AND METHOD OF OPERATION

A LIDAR system, preferably including one or more: optical emitters, optical detectors, beam directors, and/or processing modules. A method of LIDAR system operation, preferably including: determining a signal, outputting the signal, receiving a return signal, and/or analyzing the return signal.

FMCW LiDAR distance measurement apparatus
20220342071 · 2022-10-27 ·

The present invention relates to an FMCW-LiDAR distance measurement apparatus in which a light source, in particular a laser, generates a frequency modulated transmission light beam as a transmission signal having a predetermined frequency deviation and transmits said frequency modulated transmission light beam into a measurement zone; a light receiver receives light reflected by objects in the measurement zone as a reception signal; a mixer mixes at least a portion of the transmission signal with the reception signal and with an oscillator frequency to generate a mixed signal; and the oscillator frequency is adapted to a desired measurement zone to achieve a high measurement accuracy in the desired measurement zone.

Techniques for point cloud filtering

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 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 accepted or modified, the POI is transmitted to a filtered point cloud; provided the POI is rejected, the POI is prevented from reaching the filtered point cloud; provided the POI is not accepted, modified, or rejected, the POI is transmitted to a second filter.

Techniques for point cloud filtering

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 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 accepted or modified, the POI is transmitted to a filtered point cloud; provided the POI is rejected, the POI is prevented from reaching the filtered point cloud; provided the POI is not accepted, modified, or rejected, the POI is transmitted to a second filter.

RANGING SYSTEM

A ranging system includes: a source generating a wideband incident wave that is transmitted toward a target and that is reflected by the target to form a reflected wave; a feedback detector to detect the reflected wave to generate a detected signal; an operator configured to perform low-pass filtering on the detected signal at an adjustable filtering bandwidth to generate a filtered signal, and calculate cross-correlation of a feedback signal that originates from the filtered signal and a reference signal that corresponds to the incident wave to generate a cross-correlation result; and a controller calculating a distance to the target based on an operation output that originates from the cross-correlation result.