Application of Polarimetric SAR Remote Sensing to the Coastal Wetland Monitoring in South and West Coast of Korea
Sang-Eun PARK(3), Wooil M. MOON(1) and Duk-jin KIM(2)
(1) University of Manitoba, Winnipeg R3T, 2N2, Canada
(2) Korea Aerospace Research Institutes, 45 Eoeun-dong, Yuseong-gu, Daejon 305-333, Korea
(3) University of Rennes 1, Campus du Boulieu, Bat. 11C, 35042 Rennes, France
The south and western coastal zones of Korean peninsula are well known for their large tidal ranges and vast expanses of intertidal flats which play an important role in the essential function of water purification and marine products industry. Microwave remote sensing using synthetic aperture radar (SAR) system has great potential for quantitative monitoring and mapping of intertidal flats. There are now fully polarimetric space-borne SAR systems in three frequencies, X-, C-, and L-bands available for us to use, which will be an extremely valuable research tools for various disciplines of Earth sciences. Recently numerous studies using the polarimetric SAR measurements have been conducted to extract information on the surface characteristics. However, very few studies were carried out in intertidal areas in spite of their unique environment.
In this study, polarimetric air-borne and space-borne SAR measurement has been used to study the radar polarimetric characteristics in the intertidal area. The result presented in this paper is a progress report carried out in and around the Sunchon Bay in the Southern coast and Kyunggi Bay in the Western coast of the Korean peninsular. The L-band fully polarimetric NASA/JPL AIRSAR data were acquired during PACRIM-II Korea campaign, September 30, 2000. In addition, L-band PALSAR data sets have been acquired during spring and summer seasons of 2007 at Quad- and Dual-Pol modes. Theoretical models of microwave scattering from rough surfaces, such as the Integral Equation Method (IEM), the Semi-Empirical Model (SEM), and the extended Bragg model, were applied to investigate the surface roughness characteristics of intertidal zones. The vertical and horizontal roughness parameters were estimated from the circular polarization coherence as well as co- and cross polarization backscattered coefficients. Roughness inversion algorithms proposed in this paper are useful to estimate the biogenic and physical roughness structures. Recent changes in costal wetlands will be continually monitored using the PALSAR data sets together with other newly developed space-borne SAR systems such as RADARSAT-2 and TerraSAR-X.