A time to digital converter used in photon-counting LIDAR
光子计数激光雷达时间-数字转换系统

Timing system was used to measure the time of flight(TOF) of laser pulse in light detection and ranging(LIDAR). Performance of a LIDAR system is directly influenced by the properties of the timing system. A time to digital converter(TDC) based on FPGA was designed for photon counting LIDAR. By integrating the delay line interpolation into FPGA, the designed TDC could measure the TOF with fine accuracy and resolution. The performance of the TDC and its application in photon counting LIDAR were analyzed and studied experimentally. Event timing of 9 channels was implemented with this TDC, with a resolution of 29 ps and a timing accuracy of 37 ps. Using a LIDAR system equipped with the TDC, three dimensional imaging can be realized with time accuracy of 421 ps and 6.3 cm resolution in space.