基于FY-2C数据的地表温度反演验证——以黄河源区玛曲为例

Validation of FY-2C derived land surface temperature over the source region of the Yellow River: A case study of Maqu County

地表温度是气候、水文和生态等研究领域的基本参数,在地表水量和能量平衡的研究和应用中发挥着十分重要的作用。强烈的异质性是地表温度反演精度不高的主要原因之一。该文以黄河源区玛曲为研究区,评估FY-2C数据的地表温度反演精度,为将来温度反演算法和产品的进一步发展提供依据。首先,以与FY-2C相同空间分辨率的MODIS地表温度产品（MOD11B1）为地表温度真值,对反演的地表温度进行了验证;然后,利用研究区内20个采样点的土壤温度（5 cm）实测数据对反演结果进行验证。结果表明,FY-2C地表温度与MODIS温度产品具有较好的相关性,相关系数在0.72-0.95之间,均方根误差在0.44-3.87 K之间,平均均方根误差为1.90 K;反演结果和实测数据的相关系数为0.69。

Land surface temperature （ LST ） is an essential parameter in such fields of research as climate, hydrology and ecology, and it plays a significant role in the understanding of the water and energy balance of the Earth ’ s surface. Because the heterogeneity of the underlying surface is most likely a main source of the uncertainties of the satellite derived LST, this paper aims to evaluate the accuracy of the FY-2C derived LST over the heterogeneous area of Maqu County in the source region of the Yellow River and subsequently to provide solid basis for the future development of the LST inversion algorithm and product. MODIS LST product （MOD11B1） was primarily conducted to verify the FY-2C derived LST over the study area. In addition to the MODIS data, soil temperature measurements from 20 soil samples of the study area were also implemented to validate the FY-2 C derived LST. The results indicate that a significant correlation exists between the two datasets, with the coefficient of correlation, varying from 0. 72 to 0. 95, root mean square error（RMSE） ranging from 0. 44 to 3. 87 K, and the average RMSE being 1. 90 K. The FY -2C derived LST exhibits a consistent variation with the measured soil temperature, and the coefficient of correlation reaches 0. 69.