Comparison of Field Temperature versus Satellite Temperature Thermal Band in Geothermal Area

Geothermal Jaboi, Aceh is an active volcano located at the northern tip of Sumatra Island. It is very interesting for further development, as it requires researches, surveys and investigations. Geothermal appearance on the surface can be indicated by the existence of hot springs, fumaroles, hot mud and area of hydrothermal alteration. This study was conducted to identify anomaly of location based on temperature data. The objective of this study is to compare field temperature data (in situ) versus satellite temperature especially thermal band. The satellite used in this study is Landsat-5TM and the formula to convert DN to radiance is CVR = G (CVDN) + B. Where DN is digital number, CVR cell value is radiance, G is gain and B bias (or offset). The formula in thermal band (Band 6) is 0.05518 * (B1) + 1.2378. Landsat-5TM has specific gain value of 0.05518 and an offset value of 1.2378. The component (B1) is the thermal band. The DN for the thermal bands has been converted to radiance value; it will be applied to get the temperature value. The results of this study at the same location show the comparison of field temperature versus satellite temperature very significant. Data of the surface temperature measured directly almost the same with land surface temperature satellite (LST) Landsat-5TM especially the thermal band. It means trend comparison of temperature considerably increased, with the value of coefficient correlation (R-2 = 0.7719). Finally, comparison of field temperature (in situ) data with satellite Landsat-5TM data are feasible of continued at the near surface geothermal area.