A Single-Channel Algorithm for Land-Surface Temperature Retrieval From ASTER Data

This letter presents an adaptation to Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) data of the generalized single-channel (SC) algorithm developed by Jimenez-Munoz and Sobrino, also adapted to the Landsat thermal-infrared (TIR) channel (band 6) later by Jimenez-Munoz et al. The SC algorithm relies on the concept of atmospheric functions (AFs), which are dependent on atmospheric transmissivity, upwelling, and downwelling atmospheric radiances. These AFs are fitted versus the atmospheric water-vapor content for operational purposes, despite the fact that other computation options are also possible. The SC algorithm has been adapted to ASTER TIR bands 13 (10.659 mu m) and 14 (11.289 mu m), located in the typical split-window region (10.5-12 mu m), where transmission through the atmosphere is higher and surface emissivity variations are lower in comparison with the ones in the 8-9.4 mu m spectral region. Land-surface temperature retrieved with the SC algorithm has been tested over five different samples (including vegetated plots and bare soil) in an agricultural area using one single image. The comparison with ground-truth data provided a bias near to zero and standard deviations of around 2 K, with bands 13 and 14 providing similar results.