星载P波段SAR电离层效应双频校正研究

Research on spaceborne P-band SAR ionospheric effect based on dual-frequency correction

背景电离层及电离层闪烁效应对星载P波段合成孔径雷达(synthetic aperture radar,SAR)图像质量影响严重。文章针对不同信号载频、不同带宽的星载P波段SAR系统进行研究,点目标仿真结果表明,电离层效应影响程度与信号载频、带宽密切相关。通过双频方法精确测量的电离层总电子量(total electron content,TEC)对脉冲压缩匹配滤波器进行修正可实现电离层效应的校正,有效提高P波段SAR图像分辨率,得到高质量SAR图像。

The background ionosphere and ionospheric scintillation effects seriously influence the image quality of spaceborne P-band synthetic aperture radar（SAR）. For different carrier frequencies and dif- ferent bandwidths of spaceborne P-band SAR system, the results of point target simulation showed that the influence degree of ionospheric effects was closely related to the signal＇s carrier frequency and bandwidth. The pulse compression matched filters were modified through the ionospheric total elec- tron content（TEC） values which were accurately measured by the dual-frequency method so as to cor- rect the ionospheric effects. Then the resolution of P-band SAR images was improved effectively, and the high quality SAR images were achieved.