MYD10 Product File Specification
Version: V6.0.0
Revision: 2
Date: 15 January 2015
Product ID: MYD10
ESDT MYD10_L2
Product name: Snow Cover
Product Level: 2
Point of Contact: George Riggs
SSAI
NASA, GSFC, Code 971
Greenbelt, MD 20771
301-614-5650
George.A.Riggs.1@gsfc.nasa.gov
Sudipta Sarkar
SSAI
NASA, GSFC, Code 619
Greenbelt, MD 20771
301-614-6912
Sudipta.Sarkar@nasa.gov
Principal Investigator: Vincent V. Salomonson
NASA, GSFC, Code 900
Greenbelt, MD 20771
301-614-5631
Vincent.V.Salomonson@nasa.gov
Associate Investigator: Dorothy K. Hall
NASA, GSFC, Code 971
Greenbelt, MD 20771
301-614-5771
Dorothy.K.Hall@nasa.gov
Description:
A general description of the global metadata is given.
Descriptions of the SDSs are given along with a listing of the local attributes,
dimensions, and content of the SDSs.
The L2 snow cover data product is generated from swaths of MODIS L1B product
(MYD02HKM and MYD021KM) and data from the GEO product (MYD03) and the cloud mask
product (MYD35_L2). The HDF-EOS data productfile consists of 12 global attributes,
and five SDSs with local attributes.
The data product and algorithm are described in the MODIS Snow Data Product User Guide
(http//modis-snow-ice.gsfc.nasa.gov/). The user should refer to the guide
for detailed descriptions of the product, how to interpret the product, and metadata.
Only technical details of the data product content are given in this product
file specification.
Contents:
SDS names:
NDSI_Snow_Cover
NDSI_Snow_Cover_Basic_QA
NDSI_Snow_Cover_Algorithm_Flags_QA
NDSI
Latitude
Longitude
Note: The Latitude and Longitude SDSs contain coarse reslolution, 5 km
data useful for geolocating or mapping the data.
ECS Metadata:
CoreMetadata.0
ArchiveMetadata.0
StructMetadata.0
ECS Metadata
Name: Type: Num_Val: Source: Value:
CoreMetadata.0 PVL-STRING 1 SDPTK Variable
LocalGranuleID STRING 1 PGE Variable
SizeMBECSDataGranule DOUBLE 1 DSS Variable
ProductionDateTime DATETIME 1 TK Variable
DayNightFlag STRING 1 PGE Variable
ReprocessingActual STRING 1 PGE Variable
LocalVersionID STRING 1 PGE Variable
ReprocessingPlanned STRING 1 PGE Variable
ScienceQualityFlag STRING 1 DP Variable
AutomaticQualityFlagExplanation
STRING 1 PGE Variable
AutomaticQualityFlag STRING 1 PGE Variable
OperationalQualityFlagExplanation
STRING 1 PGE Variable
OperationalQualityFlag STRING 1 PGE Variable
ScienceQualityFlagExplanation
STRING 1 PGE Variable
QAPercentMissingData INTEGER 1 PGE Variable
QAPercentCloudCover INTEGER 1 PGE Variable
ParameterName STRING 1 PGE "Snow Cover"
EquatorCrossingDate DATE 1 PGE Variable
EquatorCrossingTime TIME 1 PGE Variable
OrbitNumber INTEGER 1 PGE Variable
EquatorCrossingLongitude
DOUBLE 1 PGE Variable
VersionID INTEGER 1 MCF 6
ShortName STRING 1 MCF "MYD10_L2"
InputPointer STRING 4 PGE Variable
GRingPointLatitude DOUBLE 4 PGE Variable
GRingPointLongitude DOUBLE 4 PGE Variable
GRingPointSequenceNo INTEGER 4 PGE Variable
ExclusionGRingFlag STRING 1 PGE Variable
RangeBeginningDate DATE 1 PGE Variable
RangeBeginningTime TIME 1 PGE Variable
RangeEndingDate DATE 1 PGE Variable
RangeEndingTime TIME 1 PGE Variable
PGEVersion STRING 1 PGE Variable
AncillaryInputPointer STRING M PGE Variable
AncillaryInputType STRING M PGE "Geolocation"
AssociatedSensorShortName
STRING 1 MCF "MODIS"
AssociatedPlatformShortName
STRING 1 MCF "Aqua"
AssociatedInstrumentShortname
STRING 1 MCF "MODIS"
**Product Specific Attributes (PSA)**
AdditionalAttributeName.1 STRING M PGE QAPERCENTGOODQUALITY
ParameterValue.1 STRING 1 PGE Variable
AdditionalAttributeName.2 STRING M PGE QAPERCENTOTHERQUALITY
ParameterValue.2 STRING 1 PGE Variable
AdditionalAttributeName.3 STRING M PGE GRANULENUMBER
ParameterValue.3 STRING 1 PGE Variable
AdditionalAttributeName.4 STRING M PGE SNOWCOVERPERCENT
ParameterValue.4 STRING 1 PGE Variable
End CoreMetadata.0 _________________________________
ArchiveMetadata.0 STRING 1 PGE Variable
This string will contain the following PVL fields:
AlgorithmPackageAcceptanceDate STRING 1 PGE Variable
AlgorithmPackageMaturityCode STRING 1 PGE Variable
AlgorithmPackageName STRING 1 PGE Variable
AlgorithmPackageVersion STRING 1 PGE Variable
LongName STRING 1 MCF "MODIS/Aqua Snow Cover 5-Min
L2 Swath 500m"
InstrumentName STRING 1 MCF "Moderate-Resolution
Imaging SpectroRadiometer"
LocalInputGranuleID STRING 4 PGE Variable
ProcessingCenter STRING 1 PGE "MODAPS"
ProcessingDateTime STRING 1 PGE Variable
SPSOParameters STRING 1 PGE "none"
EastBoundingCoordinate DOUBLE 1 PGE Variable
WestBoundingCoordinate DOUBLE 1 PGE Variable
NorthBoundingCoordinate DOUBLE 1 PGE Variable
SouthBoundingCoordinate DOUBLE 1 PGE Variable
ProcessingEnvironment STRING 1 PGE Variable
DESCRevision STRING 1 MCF Variable
ProductionHistory STRING 1 PGE Variable
End ArchiveMetadata.0 _________________________________
StructMetadata.0 STRING 1 HDFEOSTK
GROUP=SwathStructure
GROUP=SWATH_1
SwathName="MOD_Swath_Snow"
GROUP=Dimension
OBJECT=Dimension_1
DimensionName="Along_swath_lines_500m"
Size=4060
END_OBJECT=Dimension_1
OBJECT=Dimension_2
DimensionName="Cross_swath_pixels_500m"
Size=2708
END_OBJECT=Dimension_2
OBJECT=Dimension_3
DimensionName="Coarse_swath_lines_5km"
Size=406
END_OBJECT=Dimension_3
OBJECT=Dimension_4
DimensionName="Coarse_swath_pixels_5km"
Size=271
END_OBJECT=Dimension_4
END_GROUP=Dimension
GROUP=DimensionMap
OBJECT=DimensionMap_1
GeoDimension="Coarse_swath_pixels_5km"
DataDimension="Cross_swath_pixels_500m"
Offset=5
Increment=10
END_OBJECT=DimensionMap_1
OBJECT=DimensionMap_2
GeoDimension="Coarse_swath_lines_5km"
DataDimension="Along_swath_lines_500m"
Offset=5
Increment=10
END_OBJECT=DimensionMap_2
END_GROUP=DimensionMap
GROUP=IndexDimensionMap
END_GROUP=IndexDimensionMap
GROUP=GeoField
OBJECT=GeoField_1
GeoFieldName="Latitude"
DataType=DFNT_FLOAT32
DimList=("Coarse_swath_lines_5km","Coarse_swath_pixels_5km")
END_OBJECT=GeoField_1
OBJECT=GeoField_2
GeoFieldName="Longitude"
DataType=DFNT_FLOAT32
DimList=("Coarse_swath_lines_5km","Coarse_swath_pixels_5km")
END_OBJECT=GeoField_2
END_GROUP=GeoField
GROUP=DataField
OBJECT=DataField_1
DataFieldName="NDSI_Snow_Cover"
DataType=DFNT_UINT8
DimList=("Along_swath_lines_500m","Cross_swath_pixels_500m")
END_OBJECT=DataField_1
OBJECT=DataField_2
DataFieldName="NDSI_Snow_Cover_Basic_QA"
DataType=DFNT_UINT8
DimList=("Along_swath_lines_500m","Cross_swath_pixels_500m")
END_OBJECT=DataField_2
OBJECT=DataField_3
DataFieldName="NDSI_Snow_Cover_Algorithm_Flags_QA"
DataType=DFNT_UINT8
DimList=("Along_swath_lines_500m","Cross_swath_pixels_500m")
END_OBJECT=DataField_3
OBJECT=DataField_4
DataFieldName="NDSI"
DataType=DFNT_INT16
DimList=("Along_swath_lines_500m","Cross_swath_pixels_500m")
END_OBJECT=DataField_4
END_GROUP=DataField
GROUP=MergedFields
END_GROUP=MergedFields
END_GROUP=SWATH_1
END_GROUP=SwathStructure
GROUP=GridStructure
END_GROUP=GridStructure
GROUP=PointStructure
END_GROUP=PointStructure
End StructMetadta.0 -----------------------------------
HDF Global Attributes
L1BCalibrationQuality DFNT_CHAR 1 PGE Variable
L1BMissionPhase DFNT_CHAR 1 PGE Varialbe
L1BNadirPointing DFNT_CHAR 1 PGE Variable
L1BVersionID DFNT_CHAR 1 PGE Variable
SCF Algorithm Version DFNT_CHAR 1 PGE Variable
Surface temperature threshold
DFNT_CHAR 1 PGE Variable
Surface height threshold
DFNT_CHAR 1 PGE Variable
HDFEOS_FractionalOffset_Along_swath_lines_500m_MOD_Swath_Snow
DFNT_FLOAT32 1 PGE Variable
HDFEOS_FractionalOffset_Cross_swath_pixels_500m_MOD_Swath_Snow
DFNT_FLOAT32 1 PGE Variable
===============================================================================
SDS Definition
SDS Name: NDSI_Snow_Cover
Description: Snow cover is identified by the algorithm for every
daylight land pixel in the granule. Occurance of
snow-coverd-inland waters (snow-covered lake ice class)
is also identified. Thematic snow map is output.
Refer to the Snow Product User Guide for detailed
explanation of technique and results.
Number Type: DFNT_UINT8
Rank: 2
Dimension sizes:("Cross_swath_pixels_500m", "Along_swath_lines_500m")
Dimension Names:
Dimension0: "Along_swath_lines_500m"
Dimension1: "Cross_swath_pixels_500m"
SDS Local Attributes:
Name: Type: Num_val: Source: Value:
HDF Predefined Attributes...
long_name DFNT_CHAR string length PGE "NDSI snow cover, 500m"
units DFNT_CHAR string length PGE "none"
valid_range DFNT_UINT8 2 PGE 0,100
_FillValue DFNT_UNIT8 1 PGE 255
Custom Attributes...
Key: DFNT_CHAR8 0-100=ndsi snow, 200=missing data, 201=no decision, 211=night, 237=inland water, 239=ocean, 250=cloud, 254=detector saturated, 255=fill
Nadir_data_resolution DFNT_CHAR string length PGE "500 m"
Valid EV Obs Band 1 (%) DFNT_FLOAT32 1 PGE Variable
Valid EV Obs Band 2 (%) DFNT_FLOAT32 1 PGE Variable
Valid EV Obs Band 4 (%) DFNT_FLOAT32 1 PGE Variable
Valid EV Obs Band 6 (%) DFNT_FLOAT32 1 PGE Variable
Saturated EV Obs Band 1 (%) DFNT_FLOAT32 1 PGE Variable
Saturated EV Obs Band 2 (%) DFNT_FLOAT32 1 PGE Variable
Saturated EV Obs Band 4 (%) DFNT_FLOAT32 1 PGE Variable
Saturated EV Obs Band 6 (%) DFNT_FLOAT32 1 PGE Variable
===============================================================================
SDS Definition
SDS Name: NDSI_Snow_Cover_Basic_QA
Description: QA to show where there was good or other
quality data. Areas not processed carry special
mask values. See the Snow Users Guide for
detailed explanation.
Number Type: DFNT_UINT8
Rank: 2
Dimension sizes:("Cross_swath_pixels_500m", "Along_swath_lines_500m")
Dimension Names:
Dimension0: "Along_swath_lines_500m"
Dimension1: "Cross_swath_pixels_500m"
SDS Attributes:
Name: Type: Num_val: Source: Value:
HDF Predefined Attributes...
long_name DFNT_CHAR string length PGE "NDSI snow cover general quality value"
units DFNT_CHAR string length PGE "none"
valid_range DFNT_UINT8 2 PGE 0,4
_Fillvalue DFNT_UNIT8 1 PGE 255
Custom Attributes...
Key: DFNT_CHAR8 0=best, 1=good, 2=ok, 3=poor-not used, 4=other-not used, 211=night, 239=ocean, 255=unusable L1B data or no data
===============================================================================
SDS Definition
SDS Name: NDSI_Snow_Cover_Algorithm_Flags_QA
Description: QA to show the status of different snow test
flags and which one may have been turned on (indicating failed)
in the snow processing algorithm work-flow.
Number Type: DFNT_UINT8
Rank: 2
Dimension sizes:("Cross_swath_pixels_500m", "Along_swath_lines_500m")
Dimension Names:
Dimension0: "Along_swath_lines_500m"
Dimension1: "Cross_swath_pixels_500m"
SDS Local Attributes:
Name: Type: Num_val: Source: Value:
HDF Predefined Attributes...
long_name DFNT_CHAR string length PGE "Fractional snow cover, 500m"
units DFNT_CHAR string length PGE "none"
format DFNT_CHAR string length PGE "bit flag"
valid_range DFNT_UINT8 2 PGE 0,254
_FillValue DFNT_UNIT8 1 PGE 255
Custom Attributes...
Key: DFNT_CHAR8 bit on mean:
bit 0: inland water flag
bit 1: low visible screen failed, reversed snow detection
bit 2: low NDSI screen failed, reversed snow detection
bit 3: combined temperature and height screen failed, snow reversed because too warm and too low
This screen is also used to flag a high elevation too warm snow detection,
in this case the snow detection is not changed but this bit is set.
bit 4: too high swir screen and applied at two thresholds:
QA bit flag set if band6 TOA > 25% & band6 TOA <= 45%,
indicative of unusual snow conditon, or snow commission error;
snow detection reversed if band6 TOA > 45%
bit 5: spare
bit 6: spare
bit 7: solar zenith screen, indicates increased uncertainty in results
===============================================================================
SDS Definition
SDS Name: NDSI
Description: Raw NDSI layer, provided for user to generate their
own snow map if needed. This layer has not been filtered for anything.
Number Type: DFNT_INT16
Rank: 2
Dimension sizes:("Cross_swath_pixels_500m", "Along_swath_lines_500m")
Dimension Names:
Dimension0: "Along_swath_lines_500m"
Dimension1: "Cross_swath_pixels_500m"
SDS Attributes:
Name: Type: Num_val: Source: Value:
HDF Predefined Attributes...
long_name DFNT_CHAR string length PGE "NDSI snow cover general quality value"
units DFNT_CHAR string length PGE "none"
valid_range DFNT_INT16 2 PGE 0,10000
_Fillvalue DFNT_INT16 1 PGE 0
scale_factor DFNT_FLOAT32 1 PGE 1.0E-4
Custom Attributes...
Key: DFNT_CHAR8 0=best, 1=good, 2=ok, 3=poor-not used, 4=other-not used, 211=night, 239=ocean, 255=unusable L1B data or no data
===============================================================================
SDS Definition
SDS Name: Latitude
Description: Coarse resolution latitude data for geolocation purposes.
Number Type: DFNT_FLOAT32
Rank: 2
Dimension sizes:("Coarse_swath_lines_5km", "Coarse_swath_pixels_5km")
Dimension Names:
Dimension0: "Coarse_swath_pixels_5km"
Dimension1: "Coarse_swath_lines_5km"
SDS Attributes:
Name: Type: Num_val: Source: Value:
HDF Predefined Attributes...
long_name DFNT_INT8 1 PGE "Coarse 5 km resolution lat itude"
units DFNT_CHAR 1 PGE "degrees"
valid_range DFNT_FLOAT32 2 PGE -90.000, 90.000
_FillValue DFNT_FLOAT32 1 PGE -999.000
Local Attributes
source DFNT_CHAR 1 PGE "MYD03 geolocation product; data read from center pixel in 5 km box"
===============================================================================
SDS Definition
SDS Name: Longititude
Description: Coarse resolution longititude data for geolocation purposes.
Number Type: DFNT_FLOAT32
Rank: 2
Dimension sizes:("Coarse_swath_lines_5km", "Coarse_swath_pixels_5km")
Dimension Names:
Dimension0: "Coarse_swath_pixels_5km"
Dimension1: "Coarse_swath_lines_5km"
SDS Attributes:
Name: Type: Num_val: Source: Value:
HDF Predefined Attributes...
long_name DFNT_INT8 1 PGE "Coarse 5 km resolution long itude"
units DFNT_CHAR 1 PGE "degrees"
valid_range DFNT_FLOAT32 2 PGE -180.000, 180.000
_FillValue DFNT_FLOAT32 1 PGE -999.000
Local Attributes
source DFNT_CHAR 1 PGE "MYD03 geolocation product; data read from center pixel in 5 km box"