干旱区生态环境知识资源中心

Analyses about physical and chemical parameters of lacustrine deposits such as moisture, salinity, dielectric property and surface micro-topography, were carried out to investigate the scattering mechanisms and subsurface scattering structure in Lop Nur Lake Basin (the "Ear" region). Using PolSAR (Polarimetric Synthetic Aperture Radar) technology, physical scattering mechanisms in different texture regions were analyzed quantitatively. The calculated results of the co-polarization correlation and degree of polarization reveal that the whole "Ear" region produced strong backscattering energy, and the scattering mechanism of bright strip is more complicated than that of grey strip. The formation of "Ear" feature is apparently due to the status of surface micro-topography. Then, this paper further extracted the contributions of different scattering mechanisms using polarimetric decomposition algorithm. Based on quantitative comparison among the three parts, subsurface characteristics (e.g. : salinity) are demonstrated to be fundamental cause of "Ear" feature, with R square of 0.784. Meanwhile, the results indicate that subsurface lacustrine sediments with high moisture and salinity are important for SAR response, which are also related with surface pattern. The penetrating capability of SAR is proposed to be effective in Lop Nur Lake Basin, which means its significant potential for arid environment study.