Seasonal Change Monitoring of Wetlands by Using Airborne and Satellite Polsar Sensing

This paper presents a simple water area classification technique based on POLSAR image analysis and investigates the seasonal change of the true water area in wetland by making use of the satellite ALOS/PALSAR data, in addition to the air-borne Pi-SAR data. We here utilize the scattering power decomposition method in the image analysis, and verify that the double-bounce scattering, which can be considered as a true water area classification marker, is observed from the wetland and the surrounding emerged plants for both the airborne and satellite POLSAR data sets, even though the resolution and the incident angle are quite different. The dependency of the polarimetric scattering feature on the variation of the incident angle is also investigated by the polarimetric scattering analysis for a simplified emergent-water boundary model by using the finite-difference time-domain (FDTD) method. It is resultantly confirmed that the double-bounce scattering is utilized as a useful marker for the distinction of the true water area of the wetland even for small incident angle case.