Abstract
A remote sensing survey was conducted in the Ngada District for geothermal explo ration using JERS 1 SAR and OPS, and ASTER VNIR and TIR data. As a result, many small volcanic cones, which have diameters less than 5 km, are seen near the Baiawa in the SAR image. Some volcanic cones are aligned along the north south direction. Since the SAR has all weather observation capability, it provides us with details of the volcanic features in the study area, where it is difficult to obtain cloud-free images using optical sensors. Volcanic features are not as obvious in the OPS image compared with the SAR image because of the high sun elevation angle in tropical areas. A small high temperature anomaly is found at the Nage geothermal area using ASTER TIR, which is a new spaceborne sensor having a high spatial resolution. These results demonstrate the advantages and limitations of satellite remote sensing survey for geothermal applications.