L波段机载重轨干涉SAR系统及其试验研究

L-band Airborne Repeat-pass Interferometric SAR System and Its Experimental Study

该文介绍了一种L波段机载重轨干涉合成孔径雷达(SAR)系统及其开展的重轨干涉SAR飞行试验与数据反演研究。重点介绍了系统内定标方法、基于差分全球定位系统/惯性测量单元(DGPS/IMU)组合导航系统的重轨干涉SAR(InSAR)成像处理方法、残余运动误差(RME)估计和补偿算法以及干涉SAR模型下高程反演方法。在实测飞行试验数据中选择了两块具有代表性的试验区域,详细分析了重轨干涉SAR数据的相干性和残余运动补偿的效果,并通过干涉反演得到试验区的高程图(DEM),利用地面测量点验证得到两试验区的高程精度分别为3.40 m和2.85 m。实验结果表明该系统具有重轨干涉SAR数据获取及高精度高程反演能力,这对机载重轨干涉SAR系统设计及重点区域地形测绘具有重要借鉴意义。在飞行航迹控制较好的情况下,该系统可用于差分干涉SAR、极化干涉SAR以及层析SAR等的研究。

This paper describes the L-band airborne Synthetic Aperture Radar(SAR)system and an experimental study of repeat-pass SAR interferometry.The discussions mainly focus on the internal calibration method,the imaging method based on Differential Global Positioning System/Inertial Measurement Unit(DGPS/IMU)data,Residual Motion Error(RME)estimation and compensation,and the Digital Elevation Model(DEM)inversion method with Interferometric SAR(InSAR).Two typical test areas were chosen from the acquired SAR data for detailed analyses.The DEMs in these two areas were inversed with repeat-pass InSAR,and comparisons with the measured ground points show errors in these two areas with a standard deviation 3.40 m and 2.85 m,respectively.This demonstrates the good performance of this L-band repeat-pass interferometric SAR system.These results have important significance for the design of airborne repeat-pass InSAR systems and typical terrain mapping.When the flight tracks are under good control,this L-band SAR system is applicable in the fields of differential InSAR,polarimetric InSAR,and tomographic SAR.