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MOD10C1 and MYD10C1 Local (Snow Cover) Attributes

Local attributes describe the data and provide summary data on the results of the snow cover algorithm. Two types of local attributes are reported: HDF predefined, and custom local attributes.

HDF Predefined Local Attributes

Attribute Name Reserved Label(s) Definition Sample Value
Label long_name Long name of the SDS Snow_covered_land
Unit units SI units of the data, if any none
Format format How the data should be viewed in Fortran format notation I3
Coordinate system coordsys Coordinate system to use for the data latitude, longitude
Range valid_range Max and min values within a selected data range 0-100 for snow
0-3 for QA
Fill Value _FillValue Data used to fill gaps in the swath 255

Custom Local Attributes for Day_CMG_Snow_Cover field

Attribute Name Definition Sample Value
_MaskValue Value given to masked areas from analysis (primarily oceans) 254
_NightValue Value assigned to cells in complete darkness 111
Cell_resolution Approximate resolution of CMG cells 0.05 degrees
Water_Mask_Pct_Land_Threshold Percentage of land in the cell to be processed as land. A cell with less than this threshold is considered ocean. 12.00
Antarctic_snow_note Special note on Antarctica processing "Antarctica deliberately mapped as snow."

Custom Local Attributes for Day_CMG_Confidence_Index field

Attribute Name Definition Sample Value
_MaskValue Value given to masked areas from analysis (primarily oceans) 254
Cell_resolution Approximate resolution of CMG cells 0.05 degrees
Water_Mask_Pct_Land_Threshold Percentage of land in the cell to be processed as land. A cell with less land than this threshold is considered ocean. 12.00
Antarctic_CI_note Special note on Antarctica processing "Antarctica deliberately mapped as snow. CI set to 100."

Custom Local Attributes for Day_CMG_Cloud_Obscured field

Attribute Name Definition Sample Value
_MaskValue Value given to masked areas from analysis (primarily oceans) 254
_NotProcessValue Value assigned to cells that were not processed 252
_NightValue Value assigned to cells in complete darkness 111
Cell_resolution Approximate resolution of CMG cells 0.05 degrees
Water_Mask_Pct_Land_Threshold Percentage of land in the cell to be processed as land. A cell with less land than this threshold is considered ocean. 12.00
Antarctic_snow_note Special note on Antarctica processing "Antarctica deliberately mapped as snow. Cloud set to 252."

Custom Local Attributes for Snow_Spatial_QA field

Attribute Name Definition Sample Value
key Explanation of the 2-bit QA flag 00 = nominal
01 = suspect
10 = cloud-obscured
11 = not analyzed
_MaskValue Value given to masked areas from analysis (primarily oceans) 254
Cell_resolution Approximate resolution of CMG cells 0.05 degrees
Water_Mask_Pct_Land_Threshold Percentage of land in the cell to be processed as land. A cell with less land than this threshold is considered ocean. 12.00
Antarctic_QA_note Special note on Antarctica processing "Antarctica deliberately mapped as snow. Flag set to QAPERCENTNOTPRODUCEOTHER."