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利用Aqua卫星上同时搭载的AMSR-E和MODIS提供同步观测的微波和红外资料,反演青藏高原地区陆面微波比辐射率。结合MODIS反演的地表类型资料,分析该地区陆地微波比辐射率随地表类型、微波频率、不同时间尺度的变化特征。结果表明:该地区主要的3种地表类型中,草地比辐射率普遍高于裸地和灌木丛,并且后两者比辐射率的量值和变化趋势都很接近;陆面微波比辐射率随着频率增大而逐渐减小,并且垂直极化比辐射率随频率变化幅度较为显著。3种地表类型的比辐射率随年度变化很小,有一定的季节差异,而昼夜差异显著。不同地表的水平极化比辐射率差异幅度比垂直极化更加显著,能更有效地识别地表类型。
AMSR-E and MODIS onboard the Aqua satellite were used to simultaneously provide microwave and infrared data to retrieve the microwave emissivity over the Qinghai-Tibet Plateau. Combined with the surface type data retrieved by MODIS, the variation of terrestrial microwave emissivity with surface type, microwave frequency and different time scales was analyzed. The results showed that the emissivity of grassland was higher than that of bare land and shrub land, and the latter two were close to the values of emissivity and the changing trend. The emissivity of land surface The frequency increases and gradually decreases, and the vertical polarization ratio of emissivity with frequency range is more significant. The emissivity of the three kinds of surface types changed little with the year, with a certain seasonal difference, but significant difference between day and night. The difference between the horizontal polarization and the emissivity of different ground surface is more significant than that of vertical polarization, and the surface type can be identified more effectively.