Research on Urban Surface Emissivity Based on Unmixing Pixel
نویسنده
چکیده
Surface emissivity is a measure of inherent efficiency of land surface. It is applied to convert heat energy into radiant energy. In this study, an unmixing pixel based algorithm was proposed to compute pixel effective emissivity for Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) data within Beijing, China. In this paper, vegetation, together with water and 3 kinds of manmade materials surface distribution is estimated through a part constrained linear spectral model after PPI (Purity Pixel Indices) calculated. Sample emissivities presented in this research were extracted from Jet propulsion laboratory (JPL) spectral database. Root Mean Square Error (RSME) results of the whole study area is 0.1012, 0.0952, 0.2178, 0.0941and 0.0951 for ASTER 5 TIR (8.125~11.65μm) bands, respectively. This study suggests that this model is useful for the estimation of land surface emissivity, and it can be used as a rather simple alternative to complex algorithms.
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