Comparative satellite capabilities for remote sensing of snow cover in the Rio Grande Basin

From 1972 until near the end of the 20th century, the use of satellite data for snow cover mapping was a viableapproach under certain conditions. The spatial resolution of Landsat and the temporal frequency of NOAA-AVHRR (National Oceanic and Atmospheric Administration - Advanced Very High Resolution Radiometer) wereoptimum or possibly better than required individually, but seldom could they be exploited together. Now, with thelaunch of Terra, the forthcoming launch of Aqua, and numerous private satellites, both adequate spatial resolutionand temporal frequency is available for mapping most size basins. When these data are used in sub-pixel mappingalgorithms, detailed snow cover representations in basins smaller than 10 km2 are possible. Probably the best snowcover mapping sensor for combining reasonably high resolution (250 m) and frequent coverage (daily) is MODIS(Moderate Resolution Imaging Spectroradiometer), on board both Terra and Aqua platforms, but the choices ofsensors or satellites are numerous with most of the data being readily available to users. Comparison of the spatialresolution, observational frequency, feature detection, suitability for snowmelt runoff models, and cost will beillustrated using different size sub-basins of the Rio Grande.