Application of shannon information theory to a comparison between L- and C-band SIR-C polarimetric data versus incidence angle

The aim of this article is to present a quantitative measurement of the redundancy, or mutual information, between two different images of the same site. It is based on Shannon and Wiener information theory. In the case of polarimetric synthetic aperture radar images, we propose to compute redundancy either at the radiometric level, according to the error bar on measurement, or at the class level, according to supervised or unsupervised classification results. The advantage of the comparison at the class level is that both Polarimetric information and spatial neighborhood information are considered, and therefore the comparison is performed at a higher level of information. easurement has been applied to the study of redundancy between L and C bands from spaceborne imaging radar C images of the Orgeval test site, located in the cast of Paris (France), versus incidence angle. It is shown that the redundancy between the two bands increases from about 20% to 30% when incidence angle increases from 44° to 57°. Based on the analysis of classification results in terms of redundancy with ground truth, an interpretation of this result is proposed. Finally, the great complementarity between the two bands is used to improve classification results, by performing data fusion between the two bands.