Tomography and Ground/Volume Decomposition for Forest Biomass Retrieval

In this work we investigate the role of volume scattering obtained from tomography and ground/volume decomposition in retrieving AGB (Above Ground Biomass). Results here presented originate from the BIOMASS L2 study, aimed at defining and implementing the tomographic and interferometric processors of the BIOMASS mission. In particular we aim at discussing whether, and to what extent, ground/volume decomposition can provide a valid alternative to tomography. To do this, both are tested based on the P-Band data collected at the forest site of Paracou, French Guiana, during the TropiSAR campaign, and validated against in-situ AGB measurements in terms of correlation and sensitivity of the retrievals. Quite surprisingly, results indicate that volumebackscattered power as obtained by ground/volume decomposition is almost unsensitive to AGB, notwithstanding different solutions for volume scattering are tested, and lead to conclusion that forest structure actually plays a non-negligible role in AGB retrieval in tropical areas.