针对采用盖革模式雪崩光电二极管(Gm-APD)作为探测器的成像激光雷达,介绍了其测距原理及3D成像原理,并对如何提高其探测性能的方法进行了分析。以分析Gm-APD触发信号的统计特性为基础,对出现在距离门内不同位置目标的探测概率和虚警概率进行了研究与仿真,结果表明,目标处在距离门最前面时,探测概率受噪声水平影响最小,虚警概率受信号强度影响最大;目标靠近距离门中间位置时,探测概率随噪声水平增大下降缓慢,虚警概率随信号强度增大下降缓慢;目标处在距离门末尾时探测概率受噪声水平影响最大,而虚警概率几乎与回波信号强度无关。

The ranging and 3D principles of imaging lidar based on Geiger-mode avalanche photodiode(APD) array are introduced, and the method of increasing its detection performance is analysed. By analyzing the statistical characteristics of Gm-APD trigger signal, the detection probability and the false-alarm probability of the taget which is at different positions of range gate are researched and simulated. The result shows that when the target is at initial position of range gate, the detection probability is hardly influenced by noise while the false-alarm probability is fiercely influenced by signal; when the target is located near the mediun position of range gate, the detection probability is slowly droped while the noise increases, and the false-alarm probability is slowly droped while the signal increases; when the target is at the end of range gate, the detection probability is fiercely influenced by noise while the false-alarm probability is hardly influenced by signal.