Joint Calibration For Three-Dimensional Location And Backscatter Distortion During Sar Interferometry Mapping

During mapping a big area consisting of several interferometric SAR (InSAR) scenes, joint calibration procedure is proposed in this paper in order to achieve the accurate three-dimensional location and backscatter, and ensure their continuity among adjacent scenes. The proposed procedure contains geometric calibration and backscatter calibration. Geometric calibration deals with multiple InSAR scenes simultaneously, and allows reducing the number of required ground control points (GCPs) by using tie points (TPs). In addition, it introduces weights to calibration to discriminate GCPs and TPs with different characteristics. Backscatter calibration consists of two steps: firstly in slant-range SAR image, backscatter distortion of single scene due to antenna pattern modulation and propagation attenuation is corrected; while secondly in geocoded SAR images, backscatter adjustment among multiple scenes is carried out according to gray difference within overlapping area between adjacent scenes. Finally, the proposed procedure for generating SAR interferometry mapping products is applied to X-band airborne InSAR data and the experimental results are given.