参数弱固定法反演地表温度

Land surface temperature retrieval by weak-fixed-parameter method

提出了弱固定敏感参数、控制信息流向目标参数的地表温度反演方法.从热红外辐射传输机理出发,以MODIS为数据源,构建辐射传输方程,同时反演包括地表温度、大气平均温度、中红外(3～5μm)、远红外(8～14.5μm)6个波段的大气透过率和发射率共计14个参数.以MODTRAN模拟数据和重庆地区MODIS遥感影像为实验数据,进行参数弱固定法地表温度反演,并与劈窗算法反演结果、MODIS温度数据产品及地表实测数据进行了对比分析.实验表明,参数弱固定法反演地表温度的均方根误差达到0.57 K,精度优于传统的劈窗算法,表明了参数弱固定法反演地表温度的可行性.

A land surface temperature（LST） retrieval algorithm called week-fixed-parameter method was proposed.The new method is achieved by week-fixed sensitive parameters so as to control information flow from MODIS thermal infrared data.Based on the thermal infrared radiative transfer theory,a forward retrieval model was established and 14 parameters were retrieved together.The retrieved parameters included LST,average temperature of atmosphere,six bands＇ atmospheric transmittances and surface emissivities in mid-infrared（3～5 μm） and infrared（8～14.5 μm）.The algorithm was tested with both MODTRAN simulated data and MODIS data.Compared with that of split-window algorithm,MODIS temperature products and ground truth,the RMSE is 0.57 K,which is better than that of traditional split-window algorithm.The test indicates that the weak-fixed-parameter method is effective to retrieve LST.