SAR Tomography over Decorrelating Targets for Forestry Applications
Stefano Tebaldini(1) and Fabio Rocca(1)
(1) Politecnico di Milano, P.zza Leonardo da Vinci, 20133, Milan, Italy
This paper reports some preliminary results of a new technique to yield tomographic prospects of vegetated areas through multiple SAR observations. This technique may be regarded as a natural extension of SAR interferometry to the case where several (distributed) targets are present within the system resolution cell. For this reason, this technique may be referred to as multi-layer SAR interferometry. In this way, we are able to estimate the position of each layer in the resolution cell with potentially the same accuracy obtainable by a traditional single-layer interferometric analysis.
The algorithm proceeds in an iterative fashion. First, we retrieve a rough estimate of the position of each layer by an adaptive filtering technique. Then, a score function is optimized with respect to each layer.
Finally, once the position of the layers has been estimated, it is possible to proceed to layer separation, in such a way as to provide for a characterization of each layer in terms of backscattered power and covariance structure.
This work has been developed for the tomographical analysis of forested areas, where the interactions between ground and canopy layers is often an obstacle to achieving unbiased estimates of surface topography and biomass.
This approach will be tested through experiments over synthetic data and on a real data-set acquired by DLR’s E-SAR over the site of Remningstorp, Sweden. This work was developed as a part of the ESA project BIOSAR 2007.
Keywords: ESA European
Space Agency - Agence spatiale europeenne,
observation de la terre, earth observation,
satellite remote sensing,
teledetection, geophysique, altimetrie, radar,
chimique atmospherique, geophysics, altimetry, radar,