C-Band tomographic profiling (TP) of a conifer forest stand

Currently, many issues remain to be understood on the interaction of a radar wave with a tree canopy and the retrieval of various forest parameters. One of the most significant is forest biomass, which is of global importance in understanding carbon stocks. Biomass cannot be measured directly, but various schemes seek to determine it using backscatter strength, multi-temporal and interferometric coherence, and stand height as proxies. Because SAR provides no direct information on the height of features in a scene, complimentary interferometric techniques have been employed, of which polarimetric SAR interferometry (PolInSAR) is the most prominent such scheme. Interferometric techniques use a pair of images slightly displaced from each other in order to determine an apparent ‘effective’ scattering height within a canopy, but it provides no detail on the vertical backscatter distribution within the target´s volume.