Generation of three-dimensional deformation map at low resolution using a combination of spectral diversity via least square approach

The capability of DINSAR (Differential Interferometric SAR) for precise large-scale deformation analysis has been shown in various case studies. DINSAR has a high potential for monitoring deformation, but with a single image pair, only the velocity component parallel to the line-of-sight direction is measured. In order to retrieve the deformation velocity in both range and azimuth direction, an alternative technique for deformation analysis is the so-called spectral diversity approach. Spectral diversity is based on a phase comparison between different sub-aperture interferograms of the scene and can generally be regarded as a highperformance for estimating the mis-registration between complex SAR images. In this paper, the following questions will be discussed based on spectral diversity and DINSAR results: 1) how to implement the spectral diversity technique for achieving the most accurate results; 2) how more reliable results can be obtained by a combination of DINSAR and spectral diversity technique; 3) how to extract the full 3D deformation vector from combination of ascending/descending passes and 4) how to extract a surface deformation map if the data sets are not perfectly coherent. Finally, a statistical analysis of every individual processing step and a error propagation analysis are undertaken. In order to make a quantitative analysis of the technique, ENVISAT data sets of the Bam earthquake in Iran are used.