Vicarious Calibration of the Landsat 7 Thermal Infrared Band and LST Algorithm Validation of the ETM plus Instrument Using Three Global Atmospheric Profiles

Due to problems in the thermal infrared sensor on-board the Landsat-8 satellite, Landsat-7 (L7) can be an interesting alternative source of thermal data because it is the only source of well-calibrated, free, high-resolution data. To contribute to the quality of thermal data, a vicarious calibration (VC) of the enhanced thematic mapper instrument and a validation of the single-channel general equation and the water vapor approach algorithm in conjunction with an inversion of the radiative transfer equation (RTE) have been performed during 2013-2015 over two Spanish test sites. For this purpose, three global atmospheric profile data sets were used to better characterize the error due to atmospheric correction: 1) MODIS atmospheric product MOD07 version 5; 2) MOD07 version 6; and 3) national center for environmental prediction (NCEP) reanalysis data. The VC results show a negligible bias in our test sites while the land surface temperature algorithms validation present a root mean square error (RMSE) of 1.5 to 3 K, with the best performance for NCEP atmospheric profiles in combination with the inversion of the RTE (RMSE below 1.5 K).