A step forward beyond the classical interpretation of the coherence region in PolInSAR scattering models

Abstract:
A number of issues related to the concept of coherence region, defined as the field of values or numerical range of the polarimetric interferometry matrix, are revisited and its use by the random-volume-over-ground (RVOG), the interferometric water cloud (IWCM) and the oriented-volume-over-ground (OVOG) models is challenged. These formulations are elaborated on top of Cloude and Papathanassiou’s PolInSAR paradigm and mostly rely on the optimization of the coherence separation of the so-called scattering mechanisms within the coherence region. The main result of this study is to prove that the usual understanding of the coherence region is incorrect and that the coherence separation optimization does not produce an optimized ratio of effective surface-to-volume scattering.