Research On Time Interval Measurement For Multi-beam Single-photon LiDAR

Multi-beam single-photon radar is the most efficient lidar scheme at present.It uses the laser beam array to irradiate the target,and uses the single photon detector to detect the laser echo signal,which improves the detection sensitivity of single photon level.Multi-beam single-photon radar has many advantages,such as high sensitivity,low power consumption,light structure and so on.It has important applications in ground mapping and remote sensing imaging.Among them,multi-channel time measurement technology is one of the core technologies,which largely determines the measurement accuracy and speed of the whole system.Aiming at the important role of time measurement technology,a multi-channel time interval measurement method based on clock phase shift method is proposed.Using the high-speed parallel processing ability of FPGA,the simultaneous measurement of 100 single photon signals is realized on a single FPGA chip.The time resolution is 1.0 ns and the measurement accuracy is 360 ps@RMS,The measurement range is 64 ?s.Aiming at the development of multi-beam single-photon radar system,the 100-channel Si APD single photon detector is upgraded,and the high-power laser drive and control module is developed.Based on the 100-channel timing module developed in this paper,combined with the 100-channel single photon detector,the high-precision parallel detection and timing measurement verification experiments of echo signal are completed.The measurement accuracy of the system meets the system requirements of multi beam single photon radar,and lays a solid foundation for large-scale data acquisition,real-time processing and image display.