Comparative Analysis of Polarimetric Orientation Angle Effects on C-Band and L-Band PolSAR Data Using RADARSAT-2 and ALOS-2

This study is based on comparative analysis of Polarimetric Orientation Angle (POA) correction on RADARSAT-2 (C-band) and ALOS-2 PALSAR-2 (L-band) quad-polarimetric datasets acquired over the San Francisco Bay Area. POA estimation and unitary rotation were applied to both datasets to remove orientation-induced asymmetry and to evaluate the resulting modifications in coherency matrix elements, the imaginary component of T23, and Yamaguchi four-component decomposition outputs. The analysis shows that POA correction stabilizes the orientation field, preserves surface scattering, enhances double-bounce contributions, and suppresses orientation-driven cross-polarised power while maintaining SPAN invariance. A key comparative finding is that C-band data is more strongly influenced by POA effects than L-band, due to its higher sensitivity to man-made structures, sharp geometric edges, and fine-scale orientation variations, whereas L-band being more responsive to vegetation volume exhibits smoother and comparatively milder POA-induced distortions. The corrected decompositions provide a clearer separation of surface, dihedral, and volume scattering components and yield physically more reliable scattering signatures. Overall, the results demonstrate that POA compensation is essential for achieving consistent polarimetric interpretation and significantly enhances decomposition performance across different frequency bands.