Linear and Circular Polarization P band SAR Tomography for Tropical Forest Biomass study

Abstract:
This paper aims at investigating the potential of P-Band SAR tomography in estimating biomass in tropical rain forests. The analysis here presented is based on multi-baseline data acquired by ONERA at the test sites of Paracou and Nourages, French Guyana, in the frame of the ESA campaign TropiSAR. The favorable baseline distribution of this data set results in a tomographic vertical resolution of about 20 m, whereas forest height ranges from 20 to 40 m. These features result in the possibility to map the vertical distribution of the backscattered power in about three independent layers, without assuming any a-priori model of the forest. For both test-sites, the backscattered power associated with the volume layer (about 30 m above the ground) is observed to exhibit the highest sensitivity to forest biomass, even for high biomass values (250-500 t/ha). Furthermore, this result appears to be loosely dependent on the employed polarization, as a similar behavior is observed in both linear and circular polarization.