Linking SAR Tomography and Polarization Coherence Tomography in Forest Scenarios

Abstract

Space borne implementations of SAR Tomography (TomoSAR) for forest volumes are particularly challenging even in a single-pass case, as the estimation of 3D reflectivity has to be carried out relying on a small number of acquisitions (or interferometric coherences) and/or non-uniform baseline distributions. A way to overcome this shortcoming is to approximate the reflectivity profile by a weighted series of functions, as for example proposed in the case of Polarization Coherence Tomography (PCT). In this case the individual weights can estimated from a rather small number of interferometric coherences. In this work, we investigate how conventional TomoSAR can be linked to PCT by finding a suitable function basis. A real data analysis is carried out on TomoSAR reflectivity profiles obtained from data sets acquired in relevant airborne campaigns over different forest types.