星载双基单次航过InSAR（interferometric synthetic aperture radar）系统由于2个SAR同时对成像区域成像，所以很长一段时间内学界均认为主辅图像中引入的电离层相位一致，经过干涉处理后可以相互抵消。然而，近几年的相关研究表明，星载双基单次航过InSAR系统仍然会受到电离层效应的影响，主要包括群延迟与相位超前、闪烁现象、法拉第旋转等。与单基InSAR系统不同的是，双基单次航过系统中电离层的影响主要是由于2个雷达之间微小的入射角差异及同一时刻下电离层分布梯度所导致的。本文对双基单次航过系统中的电离层色散效应进行分析，并对单基系统中提出的基于距离向频谱分割的电离层色散效应的校正方法在双基系统中的应用进行改进，同时利用仿真验证该方法的有效性，发现其能够较好地校正双基单次航过InSAR系统中的电离层相位误差。
The images of single-pass InSAR are acquired at the same time, so it has been claimed that the images of spaceborne bistatic single-pass InSAR system is not affected by the ionosphere since the ionospheric phase can be removed by the interferometric processing. However, it has been revealed that the images of spaceborne bistatic single-pass InSAR system are still affected by the ionosphere in recent researches, such as group delay, phase advance, scintillation, and Faraday rotation. It is different from the repeat-pass system that the ionosphere effect in bistatic single-pass InSAR system is caused by the slight incidence angle difference in the two SAR and the TEC gradient. In this paper, we first analyzed the ionospheric dispersion effects in bistatic single-pass InSAR system, and then improved and simulated the range split-spectrum method in the bistatic single-pass InSAR system. It is found that the ionospheric phase in interferogram can be removed by the range split-spectrum method, and this research result has high practical value for the Lutan-1 which will be launched soon.
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