非理想情况下星载微波辐射计成像建模仿真

Modeling and Simulation of Space-Borne Microwave Radiometer Imaging Method Under Non-Ideal Conditions

针对天线和信道的非理想因素可能会改变接收信号和方向图,导致星载微波辐射计不同程度性能下降的问题,综合考虑天线匹配和信道相关性及其相互作用对微波辐射计的影响,提出一种非理想情况下的微波辐射计成像模型。采用阻抗分析法研究天线互耦和匹配方法,利用相关系数分析信道相关性,建立包含天线互耦、天线匹配和信道相关因素的完整微波辐射计成像模型。通过仿真得到不同情况下的微波辐射计反演成像效果,并对仿真结果进行了对比分析。实验结果验证了天线互耦与匹配情况和信道相关性造成的亮温反演失真,通过选择合适的天线匹配方法可以改善微波辐射计性能。

The non-ideal factors of antenna and channel may change received signal and antenna pattern, which leads to different degrees of performance degradation of space-borne microwave radiometer. To solve this problem, it is necessary to build a microwave radiometer imaging model under non-ideal conditions by considering antenna matc- hing and channel correlation effects as well as the interactions. Mutual coupling and antenna matching are studied by using impedance analytical method. The channel correlation effect is studied by using correlation coefficient. A mi- crowave radiometer imaging model with mutual coupling, antenna matching and channel correlation effects is pro- posed. The results of microwave radiometer retrieval images under different conditions are obtained and analyzed through the simulation. The simulation results show that mutual coupling, antenna matching condition and channel correlation cause the distortion of brightness temperature retrieval. The performance of microwave radiometer can be improved by choosing appropriate antenna matching m^thod.