光电系统的探测能力主要受探测天域的亮度、光电设备和探测器本身性能的影响,而探测能力主要是以信噪比来衡量。在综合了上述影响因素基础上,引入目标成像像元数N,给出了探测信噪比的理论公式;分析了背景亮度、系统参量以及像点弥散对探测能力的影响;结合实际情况,给出了目标过境时段的目标探测情况分析,理论分析得到目标在仰角30°左右可以观测,理论分析结果与实验观测基本一致。因此,该理论公式可以定量了解不同天空背景亮度、系统设计参量、各种因素引起的像点弥散对系统探测能力影响的大小,并为系统优化设计与实际工作开展提供一定的科学依据。

The detection ability of an electro-optic system is related to sky luminance, the electro-optic (EO) system and detector. The primary specification for expressing detection ability is signal-to-noise ratio. Based on analysis of the effect factors, a calculation formula of detection ability, including the imaging number, is derived. The influence of the sky luminance, parameters of the EO system, and the dispersion of the object on the detection ability is mainly analyzed. Simulation is conducted through an example according to the space object model, and the theoretical results show that the space-object can be detected when elevation is greater than 30°. Theoretical results fit with the experimental research. The effects of sky luminance, parameters of system, dispersion of imaging point on detection ability under different conditions are quantitatively learned. Moreover, the scientific basis for the optimization design of the system and development of practical work is provided.