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

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.