Optimal, space-varying spectral filtering of IFSAR data

The paper approaches the problem of pre-filtering the interferometric SAR images to remove the geometrical decorrelation. This filtering cancels the amplitude components relative to the wavenumbers not illuminated in both passes. The design of optimum space-varying linear filters is performed by estimating the interferogram, given the two data takes, with the least square error. The algorithm is flexible, being capable of handling, beside the standard stripmap-stripmap interferometry, also scan-scan, scan-strip and scan-spot interferometry. The scene topography contribution may be either derived from an external rough Digital Elevation Model or directly estimated from the data.