为了研究基于盖革模式雪崩光电二极管探测器的光子雷达的探测性能与测距精度, 采用数学建模的方法, 从系统原理与探测时序出发, 分析了长死时间、回波脉宽大于时间数字转换器分辨时间情况下目标探测概率的分布; 由统计原理与质心法, 建立了测距精度的理论模型。利用系统设计参量, 分析了回波强度、回波脉宽、噪声和回波位置等参量对探测性能和测距精度的影响。结果表明, 回波越强, 噪声越低, 回波位置越靠前, 目标探测概率越高, 虚警率越低, 探测性能越好; 回波强度和脉宽是影响测距精度的主要因素, 回波强度越强, 脉宽越窄, 测距精度越高。

In order to investigate the detection performance and range accuracy of a laser radar using Geiger mode avalanche photodiode (GM-APD) as detector, by using the method of mathematical modeling, based on the system working principle and detection time sequence, the target detection probability was analyzed under the condition that the GM-APD detector operated under long dead-time and the echo pulse width was larger than the resolving time of the time-to-digital converter (TDC). According to the statistical theory and centroid method, the theoretical model of range accuracy was established. Using the system design parameters, the influence of the echo intensity, pulse width, noise, and echo position on the range accuracy was discussed. The results show that the stronger echo intensity, the narrower echo pulse width, the lower noise and the more front echo position result in the higher target detection probability, the lower false alarm rate and the better detection performance. Echo intensity and pulse width are the main influence factors. The stronger echo intensity and the narrower pulse width result in the higher range accuracy.