Intensity and phase statistics of multi-look polarimetric SAR imagery

Polarimetric SAR data are frequently multi-look processed. The statistical characteristics of multi-look data are quite different from that of single-look data. In this paper, the authors investigate the distributions of intensity and phase. In particular, the probability density function (PDF) of the multi-look phase difference between co-polarized components is derived for the first time, and expressed in closed form. The PDF is found only depending on the complex correlation coefficient and the number of looks. Also included are PDFs of multi-look intensity and amplitude ratios. These PDFs are verified with NASA/JPL AIRSAR data. The results of this paper can also be applied to the interferometric radar for studying the decorrelation effects