Experimental characterization of spatial statistics in polarimetric multifrequency airborne SAR data

The spatial statistics in a SAR (synthetic aperture radar) image is an important parameter for the classification of different targets, in two respects: it can be an additional discriminant and it can be used as the basis in speckle filtering techniques. The authors survey some statistical image models presented in the literature, and then focus on the experimental characterization of the spatial statistics in SAR imagery. Experimental data acquired by the JPL AIRSAR multifrequency polarimetric SAR sensor within the MAESTRO-1 and MAC-Europe campaign, as well as the ESA ERS-1 data are used in the study. MAESTRO 1 was a campaign flown in 1989 and jointly funded by ESA and the CEC JRC Ispra. MAC was a multisensor airborne campaign organized by NASA in 1991. The authors characterize texture in an intensity image by 2 parameters (first order and second order statistics): the alpha parameter in the K distribution, the autocorrelation function. Methods are presented to estimate experimentally these parameters. The parameters are studied for different types of targets and as a function of other parameters, such as polarization, frequency band, viewing direction, multilook processing, spatial resolution