Evaluation of the interaction between SAR L-band signal and structural parameters of forest cover

The objective of this paper is to evaluate the interaction between backscatter (sigma degrees) from, polarimetric L-band SAR data (collected by the airborne sensor R99-B/SIPAM) and biophysical parameters of the primary forest and secondary succession sites. The area under study is located in the region of Tapajos (Brazil), where SAR data were collected in May 2005. Another approach under investigation is the evaluation of the contribution from basic backscatter mechanisms, using the Freeman-Durden decomposition technique, applied to complex SAR images, where the physiognomic-structural characteristics of the forest stands give a significant contribution. In brief, it was possible to verify that the variable "tree height" has better relations with the backscatter values, when compared to other biophysical variables, especially when the model also includes variations of the incidence angle of the stripes imaged. The decomposition technique showed that the volumetric scattering component has the strongest influence on the SAR response at primary and secondary tropical forests.