Statistical techniques for target detection in polarization diversity images

We address the problem of target detection in active polarimetric images. This technique, which has the appealing feature of revealing contrasts that do not appear in conventional intensity images, provides several images of the same scene. However, because of the presence of nonhomogeneity in the reflected intensity, it is preferable to perform target detection on the orthogonal-state contrast image, which is a measure of the degree of polarization of the reflected light when the coherency matrix is diagonal. We show that one can determine a simple nonlinear transformation of this orthogonal-state contrast image that leads to additive noise, and we then propose a simple and efficient technique for detecting targets in these images. (C) 2001 Optical Society of America.