Modeling and analyzing InSAR phase profiles at building locations

The improved ground resolution of state-of-the-art synthetic aperture radar (SAR) sensors suggests utilizing SAR data for the analysis of urban areas. Even in the case of InSAR, for building recognition usually the analysis is triggered mainly from features detected in the magnitude images. However, considering InSAR data significant phase profiles in range direction at building locations are observable. In this paper a simple model for these characteristic profiles in layover areas is proposed. The model takes into account that in layover areas a mixture of several signal sources contribute to the interferometric phase of a range cell. At building locations a combination of contributions from ground, wall, and roof is observed. The resulting phase profiles are characterized by sensor and illumination parameters as well as object parameters. In the first part of this paper, simulated phase images at building locations based on a given surface profile in range direction are presented. In the second part, real InSAR data sets of the airborne sensors AeS-1 (Intermap) and AER-II (FGAN-FHR) with a slant range resolution of 38 cm respectively 94 cm are used to calculate interferometric phase truth data which are then compared with the simulation results.