Tree Height Retrieval Using Single Baseline Polarimetric Interferometry

This work, carried out as part of the ESA-ESRIN project “Applications of SAR Polarimetry”, concerns a review of algorithms available for the quantitative inversion of polarimetric interferometric SAR data and validation of the algorithms using simulated SAR data for forest scattering. It has been shown in several recent publications that by using interferograms in multiple polarisation channels, estimation of vegetation height, underlying ground topography and mean extinction is possible. Furthermore this can be achieved with a single frequency sensor without the need for a separate reference DEM, other a priori information or the use of data specific regression formulae. Here we concentrate on forest height as a single parameter and consider the impact of temporal decorrelation and vertical structure on height estimation. This leads to three classes of height retrieval algorithm and we show quantitative comparisons between the different methods.