Land Surface Temperature Retrieval Method Based On MODIS Data

Land surface temperature is an important parameter of energy balance of land surface and plays an important role in the interaction between land surface and atmosphere, and has important significance for energy balance on land surface, widely applied in many fields especially aerography, geology,hydrology,ecology and so on.Lack of water in the soil can result in drought and cause huge loss to society especially agricultural production. Jilin province is one of internal important commodity foodstuff bases,drought disaster has obsessed the development of local agriculture and country economy for long period. In order to acquire the detailed and reliable soil water content of large scale, making use of the land surface monitoring to reflect the soil moisture indirectly has been an effective method. This paper took the western part of Jilin province as the test field,made use of the EOS MODIS thermal infrared remote sensed data and relevant practical measured ground surface data to establish the land surface temperature retrieval model. The theoretical sense and the practical value were obvious. The detailed task included the following parts:At first,compared the three algorithm of land surface temperature retrieval of existing thermal infrared remote sensed data,the split-window algorithm was choosed and two-factor model with high precision was adopted. Secondly,according to the need of algorithm,adopted the MODIS data band,calculated the reflection brightness values and radiance brightness values, and estimated the vegetation cover value through the calculation of vegetation index. The combination method was adopted based on vegetation index and land surface classification, making use of the visible light and near infrared band of the same batch of MODIS data to obtain the land surface ratio radiance. Thirdly,according to the moisture of atmosphere gained from the MODIS data,attained the atmospheric transmittance by atmosphere radiation transmit model. Finally, the land surface temperature was retrieved through the land surface temperature retrieval model and then practically measured temperature was used to analyze the precision of retrieval results.