Scattering Dominance and Power Assessment From PolSAR Data Using Complex Unitary Rotations

Abstract

This work proposes a methodology that begins by extracting a rank-deficient residue matrix by suitably subtracting a volume scattering model from the measured full-rank coherency matrix. Then, two unitary rotation matrices transform the residue matrix aiming to decorrelate single and double-bounce scattering mechanisms. The rotated residue matrix is eigen-decomposed as the sum of two rank-1 matrices. A normalized target symmetry-asymmetry difference index is proposed that is computed from the dominant rank-1 coherency matrix elements. This index relates the two Huynen parameters: the generator of target symmetry ( <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">A</i> <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sub> ) and the generator of target structure ( <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">B</i> <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sub> ). The dominant scattering power components are computed using this proposed normalized difference index. The performance of the proposed approach is evaluated using two polarimetric Synthetic Aperture Radar (PolSAR) datasets. Analysis shows that the obtained results outperform the state-of-the-art techniques.