Modification of Polarimetric SAR Interferometry Target Decomposition With Accurate Topography

In this letter, an accurate topographical phase is applied to the model-based (odd-bounce, double-bounce, and volume scattering) decomposition of synthetic aperture radar (SAR) interferometry data. The decomposition procedure considered here is a determined nonlinear equation system that can be solved numerically. The accurate topographical phase is first estimated and then used as the initial input parameter to our numerical method. This approach avoids large errors generated by the constant topographical phase in fluctuating forested areas. Additionally, the modified volume scattering model introduced by Yamaguchi et al. is applied to the polarimetric SAR interferometric target decomposition data of forested areas, rather than the purely random volume scattering of Freeman and Durden, to produce the best fit to the measured data. This method retrieves the magnitude associated with each mechanism and their heights. The quality of the decomposition is demonstrated using L-band simulated data created with PolSARproSim software and L-band airborne data (BioSAR 2008) acquired by the DLR E-SAR in the Vindeln Municipality in northern Sweden.