The main objective of this work is the investigation of the relationship between the polarimetric L-band backscatter (σº) from different incidence angles (collected by the airborne sensor R99-B/SIPAM) and the structural parameters of the primary and secondary forest typologies. The area under study is located at the Tapajós National Forest and surroundings (Pará State, Brazil). Using the Freeman-Durden target decomposition technique, the basic backscatter mechanisms are presented to verify the contributions of the physiognomic-structural components of these forest stands in the L-band signal responses. As a conclusion, it is possible to verify that the variable "tree height" has better relations with the backscatter values, when compared to other structural variables, especially when the model also includes variations of the incidence angle of the stripes imaged. The Freeman-Durden decomposition technique indicates that the volumetric scattering component has the strongest influence on the L-band at primary and secondary tropical forests at incidence angles between 52 and 70 degrees, mainly due to the high incidence angle and, consequently the low depth vertical penetration.
Forest Inventory; L-Band; SAR Data; Mapping; Tropical Forest; Amazon
