高分解能航空機搭載合成開口レーダによる汽水域観測 : 初期解析結果

High-resolution airborne SAR observations were conducted over Lakes Shinji and Nakaumi area in 2001 and 2002 using the CRL/NASDA's pi-SAR that has the capability for a simultaneous dualfrequency(L-band and X-band) and multi-polarization observation. Coupled with the pi-SAR survey, extensive in situ field measurement were also made in order to detailed analyses of pi-SAR images and back-scattering coefficients(σ^0). The preliminary analyse revealed that the SAR images L- and X-bands have somewhat different signatures suggesting that the X-band backscatter rapidly responds to fine structure of atmospheric turbulence as well as average wind field. Flow-like dark signatures are also found, suggesting the capabilities of SAR in detecting the surface slick and water flow patterns. Incidence angle, frequency and polarization dependences of σ^0 obtained from the pi-SAR are also studied. The results indicate the potential of the SAR for high-resolution wind field mapping as well as the necessity of more detailed studies of wind-water surface interactions and surface wave spectra in coastal lagoon areas where water bodies are small and surrounded by land.