Wetland Surface Temperature Estimation using EOS/MODIS Data
要旨Moderate Resolution Imaging Spectroradiometer (MODIS) has established its usefulness in various global change studies due to its spectral and temporal resolution in various regions of electromagnetic spectrum. Its utility is not only restricted to land surface studies, but also to various hydrological, ecological and environmental investigations at regional/continental level. To support these studies, a range of MODIS data products are also available freely. One of the key factors of choosing MODIS data for global environmental studies is to gather data in the thermal region of electromagnetic spectrum. Thermal characteristics in the form of surface temperature of the targeted areas have proven their significance in observing the trend in land use, surface water etc. The paper describes a methodology to estimate the Wetland Surface Temperature (WST) using thermal bands of MODIS sensor onboard the Terra satellite. This technique introduces a factor incorporating the emitting characteristics of wetland surfaces in two thermal bands (10.78µm – 11.28µm and 11.77µm – 12.27µm). A study has also been carried out to compare the temperature derived from the proposed method with the temperature derived from constant emissivity method, conditional constant emissivity method and temperature of MODIS LST product. It has been found that for wet surfaces, our proposed method provides the temperature within ±2ºC range of MODIS LST products.