单光子激光测距系统主回波重叠与应对方法

Main Wave/Echo Signal Overlapping in Single-Photon Laser Ranging System and Countermeasure

共光路单光子激光测距系统中,存在激光发射时刻与回波光子接收时刻相重叠的现象,称为主回波重叠。重叠会造成特定测距时间段回波信号的丢失,导致目标探测概率的降低。通过对测距系统的结构与工作信号时序的分析计算,研究了主回波重叠现象发生的条件,得出测距光子飞行时间与重叠现象间的关联性。阐述了激光发射调整对重叠的作用机理,给出基于激光发射时间间隔周期调整的主回波重叠的应对方法。据此开展对应的整体模拟与测距实验,结果表明该方法可在一定程度上避免主回波重叠的发生,提高目标的探测概率。

In the common-optical-path single-photon laser ranging system,there is a phenomenon that the laser emission moment overlaps the echo photon receiving time,which is called the main wave/echo signal overlapping.Overlap causes the loss of echo signals during a specific ranging period,resulting in a decrease in the probability of target detection.In this paper,the conditions for the occurrence of the main wave/echo signal overlapping phenomenon are studied by analyzing and calculating the structure of the ranging system and time sequence of signals in ranging.The correlation between the flight time of the ranging photon and the overlapping phenomenon is obtained.The mechanism of laser emission adjustment on overlapping is described,and a countermeasure for the main wave/echo signal overlapping based on the periodic adjustment of the laser emission time interval is given.Based on this,the corresponding overall simulation and ranging experiment are carried out,and the results show that the proposed method can avoid the occurrence of main wave/echo signal overlapping to a certain extent and improve the detection probability of the target.