Detection of pulse trains by time-of-flight lidar systems

Abstract

This document describes a time-of-flight lidar system configured to process pulse trains instead of individual pulses, for improved range resolution and pixel throughput. Each pulse in the pulse train is output at a respective duration and intensity, which may vary to provoke a return with a high-intensity and low signal ambiguity, prevent thermal build-up, or promote safe ocular operation. An expected intensity of the return as a function of time can be determined. By sampling reflections at the expected times and intensities, the lidar system quickly identifies a corresponding lidar return, even despite lidar noise. A return time of the return can indicate a distance or speed associated with an object pixel in a field-of-view. Processing pulse trains instead of individual pulses allows pixels to be scanned faster than using long durations or frame times, which also promotes ocular safety. Increased throughput is realized using low-energy lasers and inexpensive hardware, which minimize thermal footprint.