Accurate photo detector measurements for lidar

A light ranging system comprising:

• an illumination module comprising a light source configured to output pulses of electromagnetic radiation into a field ahead of the light ranging system;
• a sensing module comprising:
• a plurality of photosensors corresponding to different fields of view, each photosensor of the plurality of photosensors including a plurality of photodetectors that, when triggered by photons, are configured to output binary signals indicating the photons have been detected;
• timing circuitry configured to determine times for when photons are detected based on the binary signals;
• and
• histogram circuitry configured to determine and store counters that each correspond to a number of photodetectors of a photosensor triggered during a time bin for each photosensor of the plurality of photosensors, thereby creating a histogram that is usable to determine a received time of one or more pulses from the light source that reflected from an object to each photosensor of the plurality of photosensors.

A light ranging system comprising:

• a light transmitting module comprising a plurality of emitters configured to output one or more illuminating beams of light of an operating wavelength into a field ahead of the light ranging system;
• a light sensing module comprising a plurality of photosensors operable to detect photons emitted from the plurality of emitters after being reflected from surfaces within the field, each photosensor in the plurality of photosensors comprising a plurality of single photon avalanche diodes (SPADs) that, when triggered by photons, output signals indicating the photons have been detected;
• timing circuitry configured to determine times for when photons are detected based on the signals output from the plurality of photosensors;
• histogram circuitry configured to determine and store counters that each correspond to a number of SPADs of a photosensor triggered during a time bin for each photosensor of the plurality of photosensors, thereby creating a histogram that is usable to determine a received time of one or more pulses from the plurality of emitters that reflected from an object to each photosensor of the plurality of photosensors;
• and
• an electric motor operatively coupled to rotate the light transmitting module and the light sensing module about an axis,
• wherein the plurality of emitters and the plurality of photosensors are arranged to form a plurality of emitter channels and a plurality of photosensor channels, and
• wherein the light ranging system collects distance data from each channel pairing based on times between transmission of pulses from the emitter of a channel pairing and detection of photons from the pulses by the photosensor of the channel pairing.

A light ranging system comprising:

• a light transmission module comprising a plurality of emitters configured to output pulses of electromagnetic radiation into a field ahead external to the light ranging system;
• a light sensing module comprising a plurality of photosensors corresponding to different fields of view, wherein each photosensor in the plurality of photosensors comprises a plurality of photodetectors that, when triggered by photons, output signals indicating the photons have been detected;
• timing circuitry configured to determine times for when photons are detected based on the signals;
• histogram circuitry configured to determine and store counters that each correspond to a number of photodetectors of a photosensor triggered during a time bin for each photosensor of the plurality of photosensors, thereby creating a histogram that is usable to determine a received time of one or more pulses from the plurality of emitters that reflected from an object to each photosensor of the plurality of photosensors;
• and
• an electric motor operatively coupled to rotate the light transmission module and the light sensing module about an axis,
• wherein the light ranging system collects distance data based on times between transmission of the pulses of electromagnetic radiation from the plurality of emitters and detection of the photons from the pulses of electromagnetic radiation by the plurality of photosensors.