ASTERによる地表面温度および放射率の導出

抄録

This paper describes the derivation of surface temperature and surface emissivity from ASTER data. These parameters are very important in global change study as the basic physical properties. High resolution surface temperature will be one of the essential elements for the study of surface heat balance. The emissivity also has the future potential for mapping surface materials in thermal infrared region. The derivation method of these two parameters is based on the Planck's equation, and it requires an additional empirical relationship in the statistical characteristics of emissivity because this method is an underdetermined problem. Here several derivation methods, such as the model emittance, the normalization, the alpha residual and the MMD methods, are introduced as the candidates of the standard algorithms. The major objective of the project is to determine the algorithm for standard data products. Various activities are required for this purpose. The measurement of spectral characteristics of various surface materials, and the airborne experiments for the simulation study have been executed these few years. A series of airborne experiment by NASA's TIMS played an important role for the algorithm evaluation, and Japanese ASTER airborne simulator having the observation capability with high spectral resolution in TIR region was also used for the same purpose. These activities have promoted the study in thermal infrared remote sensing. Finally the problems related to atmospheric correction was pointed out for a future study.