星载光电成像系统可实现远距离空间目标的探测与识别，而探测距离是系统的主要性能参数。以空间目标反射太阳光为基础，建立了系统极限探测距离的数学物理模型，分析了影响探测距离的因素，对极限探测距离与太阳光入射方向、光学系统的有效通光口径、探测器的信噪比阈值以及曝光时间的定量关系进行了数值模拟研究。研究结果表明：增大光学系统的有效通光口径可实现系统探测能力的显著提升；当信噪比阈值和太阳光入射角同时变化时，降低信噪比阈值可有效提高系统的探测能力，并且此时太阳光入射角的变化对系统极限探测距离的影响较小。

Satellite photoelectric imaging system can detect and recognize target at long distance. Maximum detection distance is its main property parameter. Based on the sun retro-reflection light of space target, several factors including sun light incidence angle, effective aperture of optics system, detector′s signal-to-noise ratio (SNR) threshold and exposure time are analyzed to provide the mathematical model of the maximum detection distance. The results show that the limitation detection distance improves notly when the optics system effective aperture increases; the decrease in SNR threshold can improve the detection capability markedly and sun light incidence angle change has little influence when SNR threshold and sun light incidence angle vary simultaneously.