A RANGE-ELEVATION COMBINED SAR TOMOGRAPHY FOR SPARSE AIRBORNE ARRAY-INSAR IMAGES

SAR Tomograpgy is a standard tool for 3D radar imaging, which overcomes the limitation of SAR 2D geometric distortion by using the baseline diversity. Conventional multi-baseline SAR data by repeat-pass space-borne SAR mission requires a long waiting time. The new airborne array InSAR system can acquire the multi-baseline images in a single flight, which significantly improves the practical capability of SAR based 3-D reconstruction. However, the array InSAR system with many channels has very high complexity. The performance of existing algorithms decrease significantly with such a sparse acquisition. In this paper, we have proposed a Range-Elevation (R-E) combined TomoSAR algorithm aiming to solve this issue. The conventional TomoSAR imaging model is converted to a 2D spectrum estimation. The neighboring pixels in the range domain are jointly processed to get the final height estimation. The experiments using real array-InSAR data show that R-E TomoSAR has a good performance in 3-D reconstruction with few acquisitions.