Field validation of the ASTER Temperature-Emissivity Separation algorithm

The Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) has operated since 19 December 1999 from NASA's Terra Earth-orbiting, sun-synchronous satellite. The Temperature-Emissivity Separation (TES) algorithm is used to calculate surface temperature and emissivity standard products, predicted to be within +1.5 K and +0.015 of correct values, respectively. Analyses of time sequences of ASTER images showing validation sites at Lake Tahoe, California, the Salton Sea, California, Railroad Valley Nevada, and the island of Hawai?i demonstrate that TES generally performs within these limits. The validation experiments also demonstrate that, under unusual atmospheric conditions of anomalously high humidity or spatial variability, atmospheric compensation can be incomplete and errors in temperature and emissivity images can be larger than anticipated.