基于FY-3B/MWRI数据的青藏高原地区积雪深度反演

Retrieval of snow depth from FY-3B/MWRI data over the Qinghai-Tibetan Plateau

以青藏高原地区(25°N-40°N,70°E-105°E)为研究区域,基于积雪深度与微波辐射计18.7 GHz水平极化通道和36.5 GHz水平极化通道的亮温差(Tb18H-Tb36H)具有良好的线性相关性,得出了适用于FY-3B/MWRI(Microwave Radiation Imager)亮温数据反演青藏高原地区雪深的新算法.利用FY-3B/MWRI一级亮温数据,通过新的半经验算法反演了青藏高原地区的积雪深度,进而运用AMSR2(the Advanced Microwave Scanning Radiometer 2)的二级雪深产品验证了反演结果.结果表明:针对青藏高原地区,新算法相对于全球积雪深度算法具有更小的平均相对误差以及更小的均方根误差,在该研究区域具有更好的适用性.今后可以结合该地区的地表类型分类,对积雪深度反演算法进行更加细致化的拟合,以期提高反演精度,为青藏高原地球物理参数的遥感反演提供支持.

In this study, a new algorithm for FY-3 B/MWRI data inversion of snow depth over Qinghai-Tibetan Plateau is proposed based on the linear correlation between snow depth and the brightness temperature difference which is between the 18.7 GHz horizontal polarization channel and 36.5 GHz horizontal polarization channel(TB18 h-TB36 h) of the microwave radiometer. And the depth of snow cover of Qinghai-Tibetan Plateau(25°N^40°N, 70°E^105°E) is retrieved from FY-3 B/MWRI(FengYun-3 B/Microwave Radiation Imager) Level 1 brightness temperatures using the new semi-empirical inversion algorithm. Then the inversion results are verified using the Level 2 snow depth product data of AMSR2(the Advanced Microwave Scanning Radiometer 2). The results show that the new algorithm has a smaller average relative error and a smaller root-mean-square error than the global algorithm for snow depth inversion used in the Qinghai-Tibetan Plateau region, and it has a better applicability in this research area. In the future, the snow depth inversion algorithm can be fitted in a more detailed way based on the classification of surface types in the region, so as to improve the inversion accuracy and provide support for the remote sensing inversion of geophysical parameters in the Qinghai-Tibetan plateau.