Toward 3D Classification of Urban Area With Polarimetric SAR Tomography

The classification of urban areas in terms of targets identification that have similar backscattering but situated at different height position (f.i. road and roof) is still a challenging task. The synthetic aperture radar (SAR) tomography (TomoSAR) approaches estimate scene reflectivity along elevation coordinate, that brings motivation to employ these techniques in the generation of 3D land use map of observed scene. To this aim, the main purpose of this paper is to investigate how TomoSAR can be employed to distinguish different targets by taking the advantage of polarization diversity. In order to fully characterize the backscattering power from targets, and based on the polarimetric basis transformation, the concept of polarization synthesis is extended to multi-baseline polarimetric data, which typically allows construction of a cube of information with different reflectivity profiles at different polarizations. Hence, on the basis of reference targets, a similarity measure is employed to characterized the scattering mechanism of each azimuthrange-height bin. The framework is evaluated using fully polarimetric multi-baseline data by DLR's ESAR system over the city of Dresden.