Estimating Soil Temperature at Given Depth Based on RS Image and Heat Conduction Model

Many satellite images with thermal infrared band can be used to obtain the ground surface temperature, but it is difficulty to get the underground soil temperature, which is a function of time and depth. The objective of this paper is to provide a solution to convert the ground temperature derived from RS image to the soil temperature at a given depth and obtain the soil temperature difference at a higher spatial resolution. Therefore, a soil temperature model based on the basic heat conduction equation was proposed. And it is suitable for the image with thermal infrared image, e.g. TM/ETM+, ASTER or CBERS-1 image. The RMSE of estimated soil temperature at depths of 10 cm and 40 cm are 1.534 K and 2.053 K, respectively. It is found that the deeper soil depth, the higher RMSE. Because the accuracy of the proposed method still depends on the ground soil temperature derived from RS image and the mean soil temperature derived from MODIS image.