The remote sensing of topography using polarimetric SAR

A processing technique for polarimetric synthetic aperture radar (SAR) data has been developed which produces profiles of terrain slopes and elevations in the azimuthal (or along-track) direction. The technique estimates the average shift in polarimetric orientation of co-pol (or cross-pol) backscatter caused by azimuthal tilts of the scattering plane. Initial tests of this technique have been made for forested areas near Villingen/Schwenningen in Baden-Wurttemburg (Germany). Subsequent tests of the algorithm have been conducted using polarimetric SAR L-band data for a mountainous, non-forested, region in the Mojave Desert (Ft. Irwin, CA). The radar measured slope (and derived elevation) profiles have low rms errors and high correlation values when compared with digital-elevation maps (DEM) for the two areas. The algorithm is capable of adaptively transitioning from forested areas to regions with open-terrain. Complete elevation and slope mapping of the terrain in two dimensions is possible using this technique when azimuthal elevation profiles are produced throughout the range extent of the SAR image.