A lidar system for detection of a gas comprises an optical transceiver for transmitting and receiving optical radiation. A method of operating the system comprises performing spatially scanned sensing measurements of the gas across a system field of view, and analyzing the sensing measurements to determine the presence and location of excess of the gas in the system field of view. Based on the determined location, an adjusted system field of view is determined and spatially scanned sensing measurements of the gas are performed across the adjusted system field of view to obtain sensing measurements at higher spatial resolution.

A lidar system for detection of a gas comprises an optical transceiver for transmitting and receiving optical radiation. A method of operating the system comprises performing spatially scanned sensing measurements of the gas across a system field of view, and analyzing the sensing measurements to determine the presence and location of excess of the gas in the system field of view. Based on the determined location, an adjusted system field of view is determined and spatially scanned sensing measurements of the gas are performed across the adjusted system field of view to obtain sensing measurements at higher spatial resolution.

A laser interferometer that includes a light source configured to emit laser light, an optical divider configured to divide the laser light into a first optical path and a second optical path, an optical modulator being provided on the first optical path or the second optical path, including an oscillator that oscillates when a current is applied, and being configured to modulate the laser light by using the oscillator, a photoreceptor configured to receive the laser light and output a photoreception signal, the laser light being reflected by an object to be measured that is provided on the first optical path or the second optical path, and a demodulation circuit configured to demodulate, from the photoreception signal, a Doppler signal derived from the object to be measured, based on a reference signal and a modulation signal derived from the optical modulator, wherein Iq/f≤1×10.sup.−7 is satisfied, where an amplitude value of the current applied to the oscillator that is oscillating is Iq [A] and an oscillation frequency of the oscillator is f [Hz].

An electronic distance meter comprises a coupler located between a laser source and a target and adapted to divert a portion of measurement light emitted by the laser source into a calibration portion connected to a photodetector and comprising an attenuator between said coupler and said photodetector for varying the luminance value of the light passing through the calibration portion, said calibration portion having a known length and said processor being configured to perform distance measurements through the calibration portion at a variety of luminance values achieved by said attenuator to derive calibration values from said distance measurements and said known length, said processor being further configured to use said calibration values for determining a target distance based on a return pulse signal.

A distance measurement device according to the present disclosure includes: a light detection unit that receives light from a subject; a depth calculation section that calculates depth information of the subject on the basis of an output of the light detection unit; and an artifact removal section that divides an image into respective segments on the basis of the depth information and validates a segment of the respective segments in which a number of pixels exceeds a predetermined threshold and invalidates a segment in which the number of pixels is less than or equal to the predetermined threshold.

A light detection and ranging (LIDAR) system to transmit optical beams including at least two up-chirp signals and at least two down-chirp signals 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 generates a baseband signal in a frequency domain of the returned signals of the at least two up-chirp signals and the at least two down-chirp signals. The baseband signal includes a first set of peaks associated with the at least one up-chirp signal and a second set of peaks associated with the at least one down-chirp signal. The LIDAR system determines the target location using the first set of peaks and the second set of peaks.

A light detection and ranging (LIDAR) system to transmit optical beams including at least two up-chirp signals and at least two down-chirp signals 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 generates a baseband signal in a frequency domain of the returned signals of the at least two up-chirp signals and the at least two down-chirp signals. The baseband signal includes a first set of peaks associated with the at least one up-chirp signal and a second set of peaks associated with the at least one down-chirp signal. The LIDAR system determines the target location using the first set of peaks and the second set of peaks.

To suppress the deterioration of signal quality in an optical signal, a LiDAR device comprises: a signal output means 20 for outputting a first electric signal in a first period, reducing the amplitude of the first electric signal outside the first period, and then outputting a second electric signal; a modulator 30 which outputs an optical signal modulated on the basis of the first electric signal or the second electric signal; and a control means 40 for applying, to the modulator 30, a bias voltage based on the optical signal modulated on the basis of the first electric signal.

To suppress the deterioration of signal quality in an optical signal, a LiDAR device comprises: a signal output means 20 for outputting a first electric signal in a first period, reducing the amplitude of the first electric signal outside the first period, and then outputting a second electric signal; a modulator 30 which outputs an optical signal modulated on the basis of the first electric signal or the second electric signal; and a control means 40 for applying, to the modulator 30, a bias voltage based on the optical signal modulated on the basis of the first electric signal.

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.