MOD10A1 Product File Specification
Version: V5.0.5
Revision: 0
Date: 15 December 2005
ESDT: MOD10A1
Name: MODIS/Terra Snow Cover Daily L3 Global 500m SIN Grid
Level: 3
Process ID: MOD_PR10A1
Point of Contact: George Riggs
SSAI
NASA, GSFC, Code 614.1
Greenbelt, MD 20771
301-614-5650
George.A.Riggs.1@gsfc.nasa.gov
Nicolo E. DiGirolamo
SSAI
NASA GSFC Code 614.1
Greenbelt, MD 20771
301 614-5824
Nicolo.E.Digirolamo.1@gsfc.nasa.gov
Hugh Powell
301-286-2310
Hugh.W.Powell.1@gsfc.nasa.gov
Principal Investigator: Vincent V. Salomonson
NASA, GSFC, Code 610.0
Greenbelt, MD 20771
301-614-5685
Vincent.V.Salomonson@nasa.gov
Associate Investigator: Dorothy K. Hall
NASA, GSFC, Code 614.1
Greenbelt, MD 20771
301-614-5771
Dorothy.K.Hall@nasa.gov
Description:
This specification description of the MOD10A1 daily gridded snow
product describes the operational data product.
A general description of the global metadata is given.
Descriptions of the SDS structures are given along with a listing of
the local attributes, dimensions, and content of SDSs.
The daily level 3 snow cover product is archived in HDF-EOS format and
consists of 11 global metadata objects and four SDSs with local
attributes. The grid scheme used is the Sinusoidal projection.
Spatial resolution of the data product is 500 m. Each data product
file is a tile of the projection and covers a nominal size of 1100 km
by 1100 km (10 degrees by 10 degrees at the Equator).
This daily snow cover product is generated using the L2G snow data
product and L2G geoangles, surface reflectances products, land cover
data product and ancillary slope and aspect files as inputs. A
scoring algorithm based on solar elevation, distance from nadir and
observation coverage of a cell is used to select the most favorable
observation of the day from the many observations stored in the L2G
product to map snow cover for the day. Snow albedo is calculated for
all cells that are mapped as snow covered. Fractional snow cover
determined from the L2G using the same scoring algorithm as for snow
but determined for all land not obscured by cloud is also contained in
the file.
Contents:
SDS names:
Snow_Cover_Daily_Tile
Snow_Spatial_QA
Snow_Albedo_Daily_Tile
Fractional_Snow_Cover
Global Metadata:
CoreMetadata.0
ArchiveMetadata.0
StructMetadata.0
HDFEOSVersion
L2GAutomaticQualityFlag
L2GAutomaticQualityFlagExplanation
L2GCoverageCalculationMethod
L2GNumberOfOverlapGranules
L2GFirstLayerSelectionCriteria
MOD10InputGranuleNames
SCF Algorithm Version
*Start Global Attributes ===================================================
Name: Type: Num_Val: Source: Value:
CoreMetadata.0 PVL-STRING
1 TK Variable
LocalGranuleID STRING 1 PGE Variable
ProductionDateTime DATETIME1 TK Variable
DayNightFlag STRING 1 PGE Variable
ReprocessingActual STRING 1 PGE Variable
LocalVersionID STRING 1 PGE "SCF V5.0.5"
ReprocessingPlanned STRING 1 PGE Variable
ScienceQualityFlag STRING 1 DP "Not Investigated"
AutomaticQualityFlagExplanation
STRING 1 PGE "No automatic quality assessment done in the PGE"
AutomaticQualityFlag STRING 1 PGE "Passed"
ScienceQualityFlagExplanation
STRING 1 DP
OperationalQualityFlag STRING 1 PGE Variable
OperationalQualityFlagExplanation
STRING 1 PGE "See http://landweb.nascom.nasa.gov/cgi-bin/QA_WWW/qaFlagPage.cgi?sat=terra for the product Science Quality status"
QAPercentMissingData INTEGER 1 PGE 0 - 100
QAPercentCloudCover INTEGER 1 PGE 0 - 100
ParameterName STRING 2 PGE
"Snow_Cover_Daily_Tile", "Snow_Albedo_Daily_Tile"
EquatorCrossingDate DATE 32 PGE Variable
EquatorCrossingTime TIME 32 PGE Variable
OrbitNumber INTEGER 32 PGE Variable
EquatorCrossingLongitude
DOUBLE 32 PGE Variable
VersionID INTEGER 1 MCF 1
ShortName STRING 1 MCF "MOD10A1"
InputPointer STRING 5 PGE Variable
GRingPointLongitude DOUBLE 4 PGE Variable
GRingPointLatitude DOUBLE 4 PGE Variable
GRingPointSequenceNo INTEGER 4 PGE Variable
ExclusionGRingFlag STRING 1 PGE "N"
RangeEndingDate DATE 1 PGE Variable
RangeEndingTime TIME 1 PGE Variable
RangeBeginningDate DATE 1 PGE Variable
RangeBeginningTime TIME 1 PGE Variable
PGEVersion STRING 1 PGE Variable
AssociatedSensorShortName
STRING 1 MCF "MODIS"
AssociatedPlatformShortName
STRING 1 MCF "Terra"
AssociatedInstrumentShortname
STRING 1 MCF "MODIS"
**Product Specific Attibutues (PSA)**
AdditionalAttributeName.1 STRING 1 PGE QAPERCENTGOODQUALITY
Parametervalue.1 INTEGER 1 PGE 0 - 100
AdditionalAttributeName.2 STRING 1 PGE QAPERCENTOTHERQUALITY
ParameterValue.2 INTEGER 1 PGE 0 - 100
AdditionalAttributeName.3 STRING 1 PGE HORIZONTALTILENUMBER
ParameterValue.3 INTEGER 1 PGE 0-35
AdditionalAttributeName.4 STRING 1 PGE VERTICALTILENUMBER
ParameterValue.4 INTEGER 1 PGE Variable
AdditionalAttributeName.5 STRING 1 PGE TileID
ParameterValue.5 INTEGER 1 PGE Variable
AdditionalAttributeName.6 STRING 1 PGE SNOWCOVERPERCENT
ParameterValue.6 INTEGER 1 PGE 0 - 100
End CoreMetadata.0 _________________________________
Name: Type: Num_Val: Source: Value:
ArchiveMetadata.0 PVL-STRING 1 TK
CharacteristicBinAngularSize DOUBLE 1 PGE Variable
CharacteristicBinSize DOUBLE 1 PGE Variable
GeoAnyAbnormal STRING 1 PGE Variable
GeoEstMaxRMSError DOUBLE 1 PGE Variable
DataColumns INTEGER 1 PGE Variable
DataRows INTEGER 1 PGE Variable
GlobalGridColumns INTEGER 1 PGE Variable
GlobalGridRows INTEGER 1 PGE Variable
AlgorithmPackageAcceptanceDate DATE 1 PGE "2005-12"
AlgorithmPackageMaturityCode STRING 1 PGE "OPL"
AlgorithmPackageName STRING 1 PGE "MOD_PR10A1"
AlgorithmPackageVersion STRING 1 PGE "V5.0.5"
LongName STRING 1 MCF "MODIS/Terra Snow Cover Daily L3 Global 500m SIN Grid"
InstrumentName STRING 1 MCF
"Moderate Resolution Imaging Spectroradiometer"
PlatformShortName STRING 1 MCF "Terra"
LocalInputGranuleID STRING 5 PGE Variable
ProcessingCenter STRING 1 MCF "MODAPS"
ProcessingDateTime DATETIME1 PGE Variable
SPSOParameters STRING 1 PGE "none"
NorthBoundingCoordinate DOUBLE 1 PGE Variable
SouthBoundingCoordinate DOUBLE 1 PGE Variable
EastBoundingCoordinate DOUBLE 1 PGE Variable
WestBoundingCoordinate DOUBLE 1 PGE Variable
ProcessingEnvironment STRING 1 PGE Variable
DESCRevision STRING 1 MCF Variable
End ArchiveMetadata.0 _________________________________
StructMetadata.0 DFNT_CHAR8 32000
GROUP=SwathStructure
END_GROUP=SwathStructure
GROUP=GridStructure
GROUP=GRID_1
GridName="MOD_Grid_Snow_500m"
XDim=2400
YDim=2400
UpperLeftPointMtrs=(meters,meters)
LowerRightMtrs=(meters,meters)
Projection=GCTP_SNSOID
ProjParams=(6371007.181000,0,0,0,0,0,0,0,0,0,0,0,0)
SphereCode=-1
GridOrigin=HDFE_GD_UL
GROUP=Dimension
END_GROUP=Dimension
GROUP=DataField
OBJECT=DataField_1
DataFieldName="Snow_Cover_Daily_Tile"
DataType=DFNT_UINT8
DimList=("YDim","XDim")
CompressionType=HDFE_COMP_DEFLATE
DeflateLevel=9
END_OBJECT=DataField_1
OBJECT=DataField_2
DataFieldName="Snow_Spatial_QA"
DataType=DFNT_UINT8
DimList=("YDim","XDim")
CompressionType=HDFE_COMP_DEFLATE
DeflateLevel=9
END_OBJECT=DataField_2
OBJECT=DataField_3
DataFieldName="Snow_Albedo_Daily_Tile"
DataType=DFNT_UINT8
DimList=("YDim","XDim")
CompressionType=HDFE_COMP_DEFLATE
DeflateLevel=9
END_OBJECT=DataField_3
OBJECT=DataField_4
DataFieldName="Fractional_Snow_Cover"
DataType=DFNT_UINT8
DimList=("YDim","XDim")
CompressionType=HDFE_COMP_DEFLATE
DeflateLevel=9
END_OBJECT=DataField_4
END_GROUP=DataField
GROUP=MergedFields
END_GROUP=MergedFields
END_GROUP=GRID_1
END_GROUP=GridStructure
GROUP=PointStructure
END_GROUP=PointStructure
END
End StructMetadta.0 -----------------------------------
HDFEOSVersion DFNT_CHAR 1 PGE Variable
L2GAutomaticQualityFlag DFNT_CHAR 1 PGE Variable
L2GAutomaticQualityFlagExplanation
DFNT_CHAR 1 PGE Variable
L2GCoverageCalculationMethod DFNT_CHAR 1 PGE Variable
L2GNumberOfOverlapGranules DFNT_UINT32 1 PGE Variable
L2GFirstLayerSelectionCriteria DFNT_CHAR 1 PGE Variable
MOD10InputGranuleNames DFNT_CHAR 1 PGE Variable
SCF Algorithm Version DFNT_CHAR 1 PGE Variable
*End Global Attributes
============================================================================
SDS Definitions:
SDS Name: Snow_Cover_Daily_Tile
Description: This snow cover SDS is a result of finding the 'best'
observation from the MOD10L2G snow cover data product.
Number Type: DFNT_UINT8
Rank: 2
Dimension Sizes: 2400, 2400
Dimension Names:
Dimension0: "Ydim"
Dimension1: "Xdim"
SDS Local Attributes:
Name: Type: Num_Val: Source: Value:
HDF Predefined Attributes
by Reserved Label name_____
long_name DFNT_CHAR string length PGE "Snow cover extent by best observation of the day"
units DFNT_CHAR string length PGE "none"
format DFNT_CHAR string length PGE "I3"
coordsys DFNT_CHAR string length PGE "cartesian"
valid_range DFNT_UINT8 2 PGE 0,254
_FillValue DFNT_UNIT8 1 PGE 255
Custom Attributes____
missing_value DFNT_INT8 1 PGE 0
Key DFNT_CHAR string length PGE "0=missing data, 1=no decision, 11=night, 25=no snow, 37=lake, 39=ocean, 50=cloud, 100=lake ice, 200=snow, 254=detector saturated, 255=fill"
============================================================================
SDS Definition
SDS Name: Snow_Spatial_QA
Description: QA information for each cell derived from the QA information
of pixels analyized to determine the modal observation of
the cell from the L2G snow cover input data product.
Number Type: DFNT_UINT8
Rank: 2
Dimension Sizes: 2400, 2400
Dimension Names:
Dimension0: Ydim
Dimension1: Xdim
SDS Local Attributes:
Name: Type: Num_Val: Source: Value:
HDF Predefined Attributes
by Reserved Label name_____
long_name DFNT_CHAR string length PGE "Spatial QA of the observation selected for the day"
units DFNT_CHAR string length PGE "none"
format DFNT_CHAR string length PGE "I3"
coordsys DFNT_CHAR string length PGE "cartesian"
valid_range DFNT_UINT8 2 PGE 0,254
_FillValue DFNT_UNIT8 1 PGE 255
Custom Attributes____
Key DFNT_CHAR string length PGE "0=good quality, 1=other quality, 252=Antarctica mask, 253=land mask, 254=ocean mask, 255=fill"
============================================================================
SDS Name: Snow_Albedo_Daily_Tile
Description: This snow cover SDS is a result of finding the 'best'
observation from the MOD10L2G snow cover and
calculating snow albedo for it. Snow albedo
calculated only for pixels that are snow in the snow
SDS.
Number Type: DFNT_UINT8
Rank: 2
Dimension Sizes: 2400, 2400
Dimension Names:
Dimension0: "Ydim"
Dimension1: "Xdim"
SDS Local Attributes:
Name: Type: Num_Val: Source: Value:
HDF Predefined Attributes
by Reserved Label name_____
long_name DFNT_CHAR string length PGE "Snow albedo of the corresponding snow cover observation"
units DFNT_CHAR string length PGE "none"
format DFNT_CHAR string length PGE "I3"
coordsys DFNT_CHAR string length PGE "cartesian"
valid_range DFNT_UINT8 2 PGE 0,100
_FillValue DFNT_UNIT8 1 PGE 255
Custom Attributes____
missing_value DFNT_INT8 1 PGE 250
Key DFNT_CHAR string length PGE
"0-100=snow albedo, 101=no_decision, 111=night, 125=land, 137=inland water, 139=ocean, 150=cloud, 250=missing, 251=self_shadowing, 252=landmask mismatch, 253=BRDF_failure, 254=non-production_mask"
============================================================================
SDS Definitions:
SDS Name: Fractional_Snow_Cover
Description: Fractional snow is a result of finding the 'best'
observation from the MOD10L2G snow cover data product
for the day.
Number Type: DFNT_UINT8
Rank: 2
Dimension Sizes: 2400, 2400
Dimension Names:
Dimension0: "Ydim"
Dimension1: "Xdim"
SDS Local Attributes:
Name: Type: Num_Val: Source: Value:
HDF Predefined Attributes
by Reserved Label name_____
long_name DFNT_CHAR string length PGE "Fractional snow covered land for the tile"
units DFNT_CHAR string length PGE "none"
format DFNT_CHAR string length PGE "I3"
coordsys DFNT_CHAR string length PGE "cartesian"
valid_range DFNT_UINT8 2 PGE 0,254
_FillValue DFNT_UNIT8 1 PGE 255
Custom Attributes____
Key DFNT_CHAR string length PGE "0-100=fractional snow, 200=missing data, 201=no decision, 211=night, 225=land, 237=inland water, 239=ocean, 250=cloud, 254=detector saturated, 255=fill"
============================================================================