P波段星载合成孔径雷达(SAR)因其穿透特性而受到关注,但是电离层中的自由电子对P波段星载SAR电磁波的 传播有较大影响。文中结合工程适用的电离层电子浓度剖面模型,分析了背景电离层电子浓度随时空变化将会引起SAR 图像距离向的偏移,同时电离层的色散效应会导致SAR压缩后的波形展宽,使距离向的分辨率变差。仿真结果为P波段 星载SAR系统设计提供依据。

The P-band spaceborne SAR system with penetrating capabilityies is recognised, but there are superior influences on the electromagnetic wave transmission because of the ionospheric free electrons. The range deviations of the SAR image are analysed in this paper, which are brought by a spation-temporal change of the electron density, the ionosphere model applied to engineering is used in the analysis. At the same time, a range resolution is deteriorated by the ionospheric dispersion which causes the compressed pulse broadening. The simulation results provides the basis on the P-band spaceborne SAR system design.