Accounting for depolarization effects in the test for Equi- Scattering Mechanisms based on the partial target detector

Abstract:
Several POLinSAR methodologies are based on the concept of polarimetric and interferometric coherence. Many of these procedures make the assumption that the scattering mechanisms between the two interferometric passes are stable (i.e. equi-scattering mechanism, ESM). However, if the scatterers change, different algorithms must be employed. The authors already developed a test for ESM in the form of a change detector based on the perturbation analysis. The main advantage of the algorithm is its independence of changes in amplitude, focusing exclusively on the polarimetric characteristics. In the previous work, the selection of the detector parameters was performed exploiting a parameterization linking a coherent change of the scattering mechanisms to the 6 dimensional complex space of the detector. In this paper, a second parameterization (to complete the first one) is considered to take into account incoherent changes of the target. The methodology was tested using RADARSAT-2 Fine quad polarimetric data. The algorithm shows significant agreement with the expected changes.