Estimating Land Surface Temperature From Satellite Image: a Case Study of Mubi Metropolis in Adamawa State Nigeria

In the present study, a single thermal infra-red sensor (TIRS) band and two operational land imager (OLI) bands of Landsat 8 were used to estimate the land surface temperature (LST) for Mubi metropolis using the Radiative Transfer Equation (RTE) based method. Applying math algebra in ArcGIS Toolbox to transform the TIRS and OLI bands into spectral radiance and top-of-atmosphere planetary reflectance is the primary task. Using the TIRS band 10, top-of-atmosphere radiance and at-sensor brightness temperature were first calculated. The normalized difference vegetation index (NDVI), the percentage of vegetation (PV), and the land surface emissivity (LSE) are all estimated using OLI bands 4 and 5, which are then converted to the top of the atmosphere's reflectivity. The atmospheric parameters: upwelling and downwelling path radiance with atmospheric transmittance needed for the RTE to estimate the LST were retrieved from an online atmospheric correction calculator available at https://atmcorr.gsfc.nasa.gov/. The study's findings indicate that the average temperature in the studied area varied between 30.85°C and 42.19°C. The estimated LST was classified into two classes, with 51% (or 29.55 square km) of the study area having temperatures that are above average and 49% (or 28.15 square km) of the study region having temperatures that are below average. The outcome of this work was further compared with information on near-surface air temperature received from Adamawa State University's metrological station in Mubi, situated in the study region. The estimated LST was calculated for the pixel where the weather station was located. The LST at the metrological station has a pixel value of roughly 37.55 oC, whereas the metrological data recorded an instantaneous average near-surface air temperature of 30.8 oC on that day.