The angle of rotation (θ) of any object about the line of sight (LOS) is known as the polarization orientation angle (OA). The OA is found to be non-zero for undulating terrains and man-made targets oriented away from the radar LOS. This effect is more pronounced at lower frequencies (eg. L- and P-bands). The OA shift is not only induced by azimuthal slope but also by range slope. The OA shift increases the cross-polarization (HV) intensity and subsequently the co-variance or the coherency matrix becomes reflection asymmetric. Compensating this OA prior to any model-based decomposition technique for geophysical parameter estimation or classification is crucial. In this paper a new method has been proposed for OA estimation based on a stochastic distance. The OA is estimated by maximizing the Hellinger distance between the un-rotated and rotated diagonal elements of the coherency matrix.
Financed by the National Centre for Research and Development under grant No. SP/I/1/77065/10 by the strategic scientific research and experimental development program:
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