AMSR-E微波数据反演裸地地表温度算法研究

Calculation of Land Surface Temperature Based on AMSR-E Data

利用AMSR-E被动微波数据,以撒哈拉沙漠地区为研究对象,基于搭载在同一颗卫星上的AMSR-E传感器和MODIS传感器同步观测成像的特点,将MODIS数据反演得到的裸地地表温度产品进行尺度上推,作为AMSR-E像元尺度的地表真实温度,在分析AMSR-E不同通道微波探测值所包含的不同信息特点的基础上,选出反演裸地地表温度较为有效的探测通道,利用多元线性回归的方法,建立经尺度上推后对应AMSR-E尺度的MODIS地表温度与AMSR-E各通道亮温之间的对应关系,从而实现利用AMSR-E被动微波数据反演裸地地表温度的算法。经验证,反演计算的裸地地表温度误差在±3K之间。该方法不仅对时间和空间的变化有一定的适应性,而且具有一定的物理意义,反演结果可以较好地反映裸地地表温度的变化情况。

Passive microwave brightness temperatures obtained from Advanced Microwave Scanning Radiometer-Earth Observing System （AMSR-E） were used to calculate the land surface temperature of desert zone in Sahara. Taking advantage of synchronism of AMSR-E data and Moderate Resolution Imaging Spectroradiometer （MODIS） data, a regression analysis method was used to obtain the relationship between AMSR-E brightness temperatures at the top of atmosphere and the land surface temperature obtained by MODIS. Several channels of AMSR-E were chosen by analyzing the characteristics of different channels, as related with different information with their inherent polarization capability. With the combination of different channels, the land surface temperatures were retrieved from AMSR-E data in different places. The results show that the land surface temperature in desert zone could be calculated by passive microwave brightness temperatures with root mean-square errors less than 3 K. This method can be used in different places, to calculate the change of land surface temperature in desert zone effectively. The study provide some guidance in applying channels of AMSR-E.