ACCURATE LAND SURFACE-TEMPERATURE RETRIEVAL FROM AVHRR DATA WITH USE OF AN IMPROVED SPLIT WINDOW ALGORITHM

In order to retrieve accurate values of land surface temperatures from satellite thermal infrared data, it is necessary to perform atmospheric corrections. This paper describes how a differential absorption method, similar to the split window technique used over sea surfaces, can be adapted and used locally over land surfaces. Work previously performed by several authors is first described, allowing one to stress the different issues to be solved, that is, the emissivity and angular effects. A semiempirical algorithm is then described, and the results obtained with it over two test areas are then described and discussed. The proposed method allows to derive land surface temperature with an accuracy better than 1.5 K. A possible algorithm is also suggested.