A method of measuring a distance using a time of flight sensor comprising a substantially transparent cover covering a light emitter and one or more photodetectors. The method comprises emitting a series of pulses of light from the light emitter; and using the one or more photodetectors to obtain a distribution of times at which at least one photodetector of the one or more photodetectors detected photons after each emission of the series of pulses of light. If the distribution of times comprises only a single peak, the method further comprises analysing the single peak to determine if the single peak includes counts of photons reflected from a target. If the single peak includes counts of photons reflected from a target, the method further comprises measuring the separation between a reference time and a point of the single peak.

The present invention relates to the field of radar detection. Provided are a detection method and a detection apparatus. The method comprises: emitting a first waveform signal to a target to undergo detection, and receiving a second waveform signal reflected by the target on the basis of the first waveform signal, the second waveform signal carrying spatial modulation information; generating, on the basis of the second waveform signal, a detection signal corresponding to the spatial modulation information, and obtaining a signal flight time carried on the detection signal; and determining distance data of the target on the basis of multiple pieces of the spatial modulation information and signal flight times corresponding thereto.

An optical measurement device includes at least a multi-frequency laser configured to simultaneously generate a frequency-fixed carrier and at least one frequency-modulated subcarrier, an optical branching element, a dual frequency beat signal generator, a difference signal generator, and an arithmetic processing unit. Either the carrier or the subcarrier within the output light of the multi-frequency laser is used as first measurement light and either the carrier or the subcarrier having a frequency different from that of the first measurement light is used as second measurement light. The dual frequency beat signal generator separates and outputs a first complex beat signal derived from the first measurement light and a second complex beat signal derived from the second measurement light. The difference signal generator outputs a difference signal between the first complex beat signal and the second complex beat signal.

LIDAR systems are less accurate in the presence of background light which can saturate the sensors in the LIDAR system. The embodiments herein describe a LIDAR system with a shutter synchronized to a laser source. During a first time period, the laser source is synched with the shutter so that the reflections are received when the shutter is in the process of changing between on and off states, during which time a function of the shutter (e.g., a phase retardation or opacity) monotonically changes so that reflections received at different times have different time-dependent characteristics (e.g., different polarizations). To mitigate the effects of background light, during a second time period, the laser source is synched with the shutter so that the background light is measured (in the absence of the reflections) which can be used to remove the effects of the background light from a range measurement.

A vehicle, Lidar system and method of detecting an object is disclosed. The Lidar system includes a photonic chip, and a laser integrated into the photonic chip. The laser has a front facet located at a first aperture of the photonic chip to direct a transmitted light beam into free space. A reflected light beam that is a reflection of the transmitted light beam is received at the photonic chip and a parameter of the object is determined from a comparison of the transmitted light beam and the reflected light beam. A navigation system operates the vehicle with respect to the object based on a parameter of the object.

To provide a device for measuring a time of passage that is capable of sensing passage of the torso more accurately than a photoelectric cell while maintaining the ease of use of a photoelectric cell, passage of a runner is sensed by causing the upper portion of the body of the runner to be broadly illuminated by infrared light, visible light, and/or other such electromagnetic waves, and by detecting light reflected from large part(s) of the body of the runner.

A vehicle, Lidar system and method of detecting an object is disclosed. The Lidar system includes a photonic chip having a laser, an on-chip frequency shifter, a combiner and a first set of photodetectors. The laser generates a transmitted light beam and an associated local oscillator beam within the photonic chip. The on-chip frequency shifter shifts a frequency of the local oscillator beam. The combiner combines a reflected light beam with the frequency-shifted local oscillator beam, wherein the reflected light beam is a reflection of the transmitted light beam from the object to generate a first electronic signal at the first set of photodetectors. A processor obtains a first measurement of a parameter of the object from the first electronic signal. The vehicle includes a navigation system for navigating the vehicle with respect to the object using at least the first measurement of the parameter.

A lidar system, preferably including one or more transmit modules, beam directors, and/or receive modules, and optionally including one or more processing modules. A method of lidar system operation, preferably including: emitting light beams, receiving reflected light beams, and/or analyzing data associated with the received light beams.

Embodiments of the present disclosure provide a method and apparatus for detecting an obstacle. The method may include: acquiring first point cloud data collected by a first vehicle-mounted laser radar and second point cloud data collected by a second vehicle-mounted laser radar, where a height of the first vehicle-mounted laser radar from a ground is greater than a height of the second vehicle-mounted laser radar from the ground, and a number of wiring harnesses of the first vehicle-mounted laser radar is greater than a number of wiring harnesses of the second vehicle-mounted laser radar; performing ground estimation based on the first point cloud data; filtering out a ground point in the second point cloud data according to the ground estimation result of the first point cloud data; and performing obstacle detection based on the second point cloud data after the ground point is filtered out.

A spatial recognition device provided with an analysis unit configured to acquire, from an optical device which receives reflected light obtained by radiating light onto a reflective plate provided on a moving body positioned within a detection area, reflected light information obtained based on the reflected light in accordance with a radiation direction of the light, and analyze a state of the moving body on which the reflective plate is provided, based on a distribution of the reflected light information at coordinates within the detection area.