雷达卫星SAR与防卫气象卫星SSM/I对渤海海冰的观测研究

用雷达卫星(RADARSAT)合成孔径雷达(SAR)和防卫气象卫星(DMSP)特别微波成像辐射计(SSM/I)在1999年1月23日同一天对中国渤海区域海冰的观测数据，进行了主动SAR与被动SSM/I的组合研究.用一层海冰电磁散射辐射的建模与数值模拟，分析了中纬度渤海沿岸海冰的特征性变化，提出用SSM/I辐射亮度温度的散射指数、极化指数、极化比率来识别渤海海冰；用RADARSAT高分辨率SAR数据(水平极化后向散射系数)对渤海海冰物理特征进行识别与分类.这些特征指数在时间与空间尺度上的相关变化可有效地应用于渤海海冰的监察.

OBSERVATIONS OF RADARSAT SAR AND DMSP SSM/I OVER SEA ICE OF CHINA'S BOHAI SEA

The shoreice at middle latitudes, such as in the China’s Bohai Sea, Huanghai Sea, is lasted only for few months during the winter. Its physical constitutes and temporal spatial variability are different from the polar regions. In this paper the sea ice detection and classification are presented on the basis of the image data from active RADARSAT SAR and passive DMSP SSM/I measurements over the Bohai Sea ice in January 23, 1999. By using numerical modeling of scattering and radiative transfer of a layer of sea ice, characteristic variation of the Bohai Sea shoreice is studied. The scattering index （ SI ）, polarization index （ PI ）, and the polarization ratio （ P R） from passive observation of the brightness temperature （ T B） are defined to detect the existence of sea ice. Further, using cohorizontally polarized back scattering （ σ hh ） measured by the RADARSAT high resolution SAR, the sea ice of the Bohai Sea can be further classified. Temporal and spatial variations of these indexes can be used to monitor the sea ice of the Bohai Sea.