Polarimetric orientation angle shifts induced by building orientation for multi-look polarimetric SAR data and its impacts on model-based decompositions

摘要

Building orientations with respect to the radar look direction is a critical influence on the interpretation of PolSAR data in urban areas. In this paper, we try to analyze thoroughly the problems of polarimetric scattering mechanism in urban areas induced by building orientation. For multi-look PolSAR data, the polarimetric scattering mechanism in urban areas is modeled by two double-bounce scatterings from two orthogonal dihedral structures. From the model, it can be inferred that with the increase of the building orientation, the POA estimation circular-polarization method and the dominant scattering mechanism labeling technique based on the model-based decompositions will gradually become invalid. Moreover, the POA compensation processing is helpful to reduce the impacts of the building orientation, but when the building orientation is increased to some degree, it also become invalid. Three L-band datasets of San Francisco acquired by AIRSAR are used to verify the inferences.