Temperate East Asia Snow and Ice Cover

Twenty-seven 10-day synthesis products of VEGETATON sensor (VGT-S10)
on SPOT 4 satellite were acquired for land cover characterization in
temperate East Asia. The 10-day VGT-S10 composites have a spatial
resolution of 1 km and are generated based on the maximum NDVI values
during the 10-day period (see SPOT website, "http://www.spot.com", for
more info). The primary emphasis of this project was to develop a
dataset which describes the spatial distribution and seasonal dynamics
of snow and ice cover in the alpine regions of east Asia. These data
are critically needed by the climate and hydrological modeling
communities. A Snow/Ice Cover data set is currently available in this
collection. The Snow/Ice Cover data set contains two variables: 1) A
normalized difference snow and ice index (NDSII) and 2) a snow and ice
cover thematic map. The NDSII was calculated from band reflectance
data from each of the 27 10-day composites acquired during the time
period. Snow and ice coverage maps were generated for each of the 27
composites by assigning snow/ice cover to pixels which had an NDSII >=
0.40 and a Band 3 value (NIR reflectance) > 0.11. Each of the two
variables has 27 holdings representing images for each 10-day
composite period between March 1, 1999 and November 30, 1999. These
data are provided in the Lambert Azimuthal Equal Area projection at a
1 km resolution.