APPLICATION OF SHANNON-INFORMATION THEORY TO A COMPARISON BETWEEN L-BAND AND C-BAND SIR-C POLARIMETRIC DATA VERSUS INCIDENCE ANGLE

The aim of this article is to present a quantitative measurement of th e redundancy, or mutual information, between two different images of t he 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 th e error bar on measurement, or at the class level, according to superv ised or unsupervised classification results. The advantage of the comp arison at the class level is that both polarimetric information and sp atial neighborhood information are considered, and therefore the compa rison is performed at a higher level of information. This measurement 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 i n the east 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 degrees to 57 degrees. Based on the analysis of classification results in terms of redundancy with gr ound truth, an interpretation of this result is proposed. Finally, the great complementarity between the two bands is used to improve classi fication results, by performing data fusion between the two bands. (C) Elsevier Science Inc., 1997.