2004 Volume 43 Issue 6 Pages 7-19
Newly launched sensors such as Terra ASTER or Terra/Aqua MODIS have channels to cover short wave infrared (SWIR) which is sensitive or effective to detect water condition on the land surface. In this study, firstly, a set of normalized indices including normalized difference vegetation index (NDVI), normalized difference soil index (NDSI) and normalized difference water index (NDWI), collectively called NDXI, were newly introduced by extending the idea of NDVI using SWIR channels. Secondly, their behavior were investigated for a variety of eleven spectral signatures observed at the ground level. It was found that NDXI were highly correlated with the existence of vegetation, soil and water. Thirdly, the compatibility of typical optical sensors were evaluated using the spectral response of ASTER, AVHRR, ETM and MODIS. Finally the atmospheric effects were evaluated using radiative transfer simulation under a variety of aerosol, visibility, topography and sun-target-sensor geometry.