中文摘要：

点目标的探测是红外成像探测系统的重要课题。以点扩散函数作用下点源目标像的照度分布函数为基础，综合考虑像的照度分布与单元探测器的位置关系，结合探测器的光电转换原理，建立了红外焦平面探测器点源光信号到电信号的转换关系；并在此基础上结合探测器的噪声模型，建立了点源信噪比模型。仿真计算结果表明：点源目标的探测信噪比与光学系统点扩散函数、单元探测器尺寸、视线偏移密切相关。该研究可为点目标红外成像探测距离的精确估计提供理论支持。

英文摘要：

The detection of point target is always an important research subject of infrared imaging system. Based on the irradiation distribution function of point target under action of point spread function, considering the positional relationship of irradiation distribution and unit detector,according to photoelectric conversion relation,the transformational relation of optical signal to electrical signal of point source detected by IRFPA was established. then, combining with detector noise model, new SNR model of point target was showed. There was a conclusion that detective point target SNR was closely related to point spread function, size of unit detector and line -of -sight displacement. This method could be a fundamental of accurate estimate of view range of infrared imaging system.