The multilook polarimetric whitening filter (MPWF) for intensity speckle reduction in polarimetric SAR images

The polarimetric whitening filter (PWF) proposed by Novak et al. is extended to the multilook case to form a multilook PWF (MPWF) for intensity speckle reduction in multilook polarimetric synthetic aperture radar (SAR) images. The MPWF optimally processes the multilook covariance matrix to generate a minimum-speckle intensity image. The amount of speckle reduction achievable by using the MPWF is quantified. We also show that the MPWF is equivalent to a maximum likelihood (ML) filter. Experimental results with the NASA/Jet Propulsion Laboratory (JPL) airborne L-band, four-look polarimetric SAR data demonstrate the effectiveness of the MPWF. Index Terms - Maximum likelihood (ML) estimation, multilook processing, polarimetric synthetic aperture radar (SAR), speckle reduction, texture.