Assessment of temporal decorrelation in differential SAR tomography for forestry applications

Differential synthetic aperture radar tomography (TomoSAR) has been proven to be effective in characterizing the bi-dimensional spatial-temporal backscattering from the distributed volumetric media. The purpose of this paper is to investigate the effectiveness of differential SAR tomography under the presence of temporal decorrelation. Under the assumptions of short and long terms decorrelation (due f.i. to motion caused by winds, or to dielectric changes caused by temporal changes of the scattering properties, or to sudden decorrelation induced by rain, snow and deforestation), differential SAR tomography using model-based Capon focusing technique is evaluated for volumetric media characterization and sub-canopy ground monitoring. he analysis is performed by simulating the temporal decorrelation with different terms and including the dependence on the vertical structure of volumetric media. This is a very important aspect to be taken into account for the assessment of different sources of decorrelation in forest reality. Moreover, the experiment is extended to the P-band data set relative to the forest site of Remningstorp, Sweden, acquired by German Aerospace Center's E-SAR airborne system in the framework of the European Space Agency (ESA) campaign BioSAR.