Agricultural field observation by space and airborne polarimetric L-band SAR data

Full polarimetric space- and air-borne L-band SAR data acquired on the same day were analyzed. The target areas were agricultural fields, including paddy in the maturation stage, that were severely damaged by a tsunami three years earlier. Lodging of paddy was found in some fields. Three-and four-component decomposition and eigenvalue-eigenvector decomposition analysis were performed. On paddy fields, the dominant component was double-bounce scattering. Paddy fields including lodged paddy showed larger volume scattering ratio than paddy fields without lodged paddy in Pi-SAR-L2 data. On soybean, weed, and bare-soil fields, surface scattering was dominant in a four-component decomposition. Paddy field and other fields were separated by a threshold of alpha angle in the eigenvalue-eigenvector decomposition. Subtle differences were found although PALSAR-2 and Pi-SAR-L2 data behaved almost similarly. L-band SAR is suitable for rice field extraction during this season.