Improving ranging performance of SiPM LiDAR in low SNR conditions through an echo processing method and laser pulse modulation

Due to its numerous advantages such as high gain and low operating bias, the silicon photomultiplier (SiPM) holds great potential in LiDAR applications. However, it is more jittery at weak echoes and more sensitive to ambient light, making its ranging performance at low signal-to-noise ratios (SNRs) severely deteriorated. To enhance the ranging performance of SiPM LiDAR under low SNR, a novel echo processing method, to the best of our knowledge, was proposed based on the statistical property of SiPM responses and validated under relatively intensive sunlight (>50k l x) using a self-developed LiDAR system. At the same time, laser pulse width modulation and multi-pulse laser emission are used in ranging experiments to maximize the advantages of this method. It has shown that increasing the laser pulse width within a certain range can improve ranging performance, and that emitting multiple laser pulses improves ranging performance more significantly. Utilizing a three-pulse laser with a peak power of only 3.2 W, a target 122 m away was ranged with a precision of 6.53 cm with only five accumulations.