Photon echo probability distribution characteristics and range walk error of small translational target for photon ranging

The photon counting Lidar enhances the signal-to-noise ratio of the echo signal and reduces the number ofphotons required for signal analysis, thereby improving the detection range and measurement accuracy. Atpresent, the photon counting Lidar is mainly used to detect stationary targets, and the mechanism of theinfluence of long-distance target motion characteristics on the photon echo probability distribution is stillunclear. Therefore, it is urgent to study the photon ranging performance of long-distance moving targets.In this paper, the probability distribution model of photon detection echo of moving targets is established,and a Monte Carlo model for photon detection of arbitrary targets is given. Through experimental comparison,the correctness of the Monte Carlo simulation model is verified. Furthermore, the probability distributioncharacteristics of the laser echo and photon echo of a small rectangular target in translation within a detectionperiod are compared. And the variation law of the probability distribution of photon detection under differenttranslational speeds is analyzed. In addition, the relationship between the photon ranging error and thetranslational speed of the target is discussed.1/1025m/s6:72cm1/2The results show that the photon echo probability distribution of the translational target is more forwardand the width is narrower than the laser pulse echo probability distribution. Compared with the extendedtarget, the detection probability of the translational small target is significantly reduced, and the maximumaverage echo photon number is times that of the extended target, as a result, the photon detection of thetranslational target requires higher laser pulse energy. When the length of target is 1m, the range walk errorreaches a maximum value at a speed of , i.e. , which is times that of the extended target.With the increase of the translational speed, the range walk error first increases and then turns stable with thelight spot acting as the boundary.The method proposed in this paper can be further extended to photon detection and ranging of targetswith other shapes, materials and attitudes. The research results provide a theoretical basis for the correctionand performance improvement of the photon ranging of moving target. Furthermore, it lays the foundation forthe detection of moving targets and accurate acquisition of information by photon counting Lidar.