A mono-window algorithm for retrieving land surface temperature from Landsat TM data and its application to the Israel-Egypt border region

Remote sensing of land surface temperature (LST) from the thermal band data of Landsat Thematic Mapper (TM) still remains unused in comparison with the extensive studies of its visible and near-infrared (NIR) bands for various applications. The brightness temperature can be computed from the digital number (DN) of TM6 data using the equation provided by the National Aeronautics and Space Administration (NASA). However, a proper algorithm for retrieving LST from the only one thermal band of the sensor still remains unavailable due to many diYculties in the atmospheric correction. Based on thermal radiance transfer equation, an attempt has been made in the paper to develop a mono-window algorithm for retrieving LST from Landsat TM6 data. Three parameters are required for the algorithm: emissivity, transmittance and eVective mean atmospheric temperature. Method about determination of atmospheric transmittance is given in the paper through the simulation of atmospheric conditions with LOWTRAN 7 program. A practicable approach of estimating eVective mean atmospheric temperature from local meteorological observation is also proposed in the paper when the in situ atmospheric proŽ le data is unavailable at the satellite pass, which is generally the case in the real world especially for the images in the past. Sensitivity analysis of the algorithm indicates that the possible error of ground emissivity, which is diYcult to estimate, has relatively insigniŽ cant impact on the probable LST estimation error dT , which is sensible to the possible error of transmittance 6 and mean atmospheric temperature dT a . Validation of the simulated data for various situations of seven typical atmospheres indicates that the algorithm is able to provide an accurate LST retrieval from TM6 data. The LST diVerence between the retrieved and the simulated ones is less than 0.4°C for most situations. Application of the algorithm to the sand dunes across the Israel–Egypt border results in a reasonable LST *Current address of Z. Qin is SMC, the Spatial Modelling Center, Box 839, S-981 28 Kiruna, Sweden; e-mail: [email protected] †e-mail: [email protected] International Journal of Remote Sensing ISSN 0143-1161 print/ISSN 1366-5901 online © 2001 Taylor & Francis Ltd http://www.tandf.co.uk/journals DOI: 10.1080/01431160010006971