相干探测小目标回波接收视场影响因素研究

Influence Factors of Receiving Field of Coherent Detected Small Target Signals

首先推导了角度失配情况下的相干效率,然后对最优相对孔径与相干效率的关系以及相干效率与失配角的关系进行仿真,最后对本振光离焦对相干效率和接收视场的影响进行评估。结果表明,理想情况下相干探测的天线口径与接收视场成反比,而且本振光离焦情况下的接收天线总体性能不会优于同等有效相干效率下的小口径接收。研究结果可为相干探测系统与光电系统性能指标的匹配设计提供理论依据,同时对相干探测的接收光学系统设计、装调和测试具有重要的指导意义。

Firstly the coherent efficiency with mismatching angle is deduced theoretically.Secondly the relationship between the optimal relative aperture and coherent efficiency and the relationship between coherent efficiency and mismatching angle are simulated.Finally the influence on coherent efficiency and receiving field when local oscillator is out of focus is evaluated.The results show that the receiving field of coherent detection is inversely proportional to antenna aperture in ideal conditions and the overall performance of receiving antenna when local oscillator is out of focus is no better than that of small-aperture antenna when the effective coherent efficiency is identical.The results can serve as a theoretical basis of matching design between coherent detection system and optoelectronics system and provide guidance on the antenna design adjustment and measurement of coherent detection.