Analytic models and postprocessing techniques for UWBSAR

The latest generation of fully polarimetric, ultra wideband (UWB), wide ang le, low frequency, foliage and ground-penetrating synthetic aperture radars (SARs) record huge amounts of data that must he processed to focus high qu ality images. At the same time only a few small subimages contain important information. We investigate the relationship between the focused image and the reflectivity profile and show that a linear shift-invariant model adeq uately represents the overall process when the focusing is done with a back projection algorithm over a constant integration angle, The derived signal model can be used to replace many computationally expensive processing tech niques, previously performed on the raw data, with equivalent postprocessin g algorithms which can be applied selectively to subimages.