The data set is from February 24, 2000 to December 31, 2004, with a resolution of 0.05 degrees. MODIS data, with a data format of. HDF, can be opened with hdfview. The data quality is good. The missing dates are as follows: 2000：1-54, 132, 219-230, 303, 2001：111, 167-182, 2002：079-086, 099, 105, 2003：123, 324, 351-358, 2004：219, 349. The number after middle age is the nth day of the year

Pixel values are as follows:

0: Snow-free land 1-100: Percent snow in cell

111: Night

252: Antarctica

253: Data not mapped

254: Open water (ocean)

255: Fill

An example of file naming is as follows:

Example: "MOD10C1.A2003121.004.2003142152431.hdf"

Where:

MOD = MODIS/Terra

2003 = Year of data acquisition

121 = Julian date of data acquisition (day 121)

004 = Version of data type (Version 4)

2003 = Year of production (2003)

142 = Julian date of production (day 142)

152431 = Hour/minute/second of production in GMT (15:24:31)

The corner coordinates are:

Corner Coordinates:

Upper Left ( 70.0000000, 54.0000000)

Lower Left ( 70.0000000, 3.0000000)

Upper Right ( 138.0000000, 54.0000000)

Lower Right ( 138.0000000, 3.0000000)

Where upper left is the upper left corner, lower left is the lower left corner, upper right is the upper right corner, and lower right is the lower right corner.

The number of data rows and columns is 1360 and 1020 respectively

Geographic longitude and latitude coordinates, the specific information is as follows:

Coordinate System is:

GEOGCS["Unknown datum based upon the Clarke 1866 ellipsoid",

DATUM["Not specified (based on Clarke 1866 spheroid)",

SPHEROID["Clarke 1866",6378206.4,294.9786982139006,

AUTHORITY["EPSG","7008"]]],

PRIMEM["Greenwich",0],

UNIT["degree",0.0174532925199433]]

Origin = (70.000000000000000,54.000000000000000)