A Comparison of Function Bases For Polarization Coherence Tomography in Forest Scenarios

Polarization Coherence Tomography (PCT) addresses the TomoSAR inversion by approximating the unknown vertical reflectivity profile by a weighted series of functions constituting a basis. The individual weights can be estimated from the available interferometric coherences. This concept becomes particularly suitable for space borne TomoSAR implementations over forest volumes in which the reflectivity profiles have to be estimated relying on a small number of acquisitions (or interferometric coherences) and/or non-uniform baseline distributions. However, the choice of an adequate (orthogonal) basis suitable for forest scenarios is still an open point. In this work, we compare different alternatives on a real data set acquired in an airborne campaign over a temperate forest.