MYD13C1 Product File Specification
Version: V6.0.0
Revision: 1.1.0
Date: 13 January 2005
ESDT: MYD13C1
Product name: MODIS/Aqua Vegetation Indices 16-Day L3 Global 0.05 Deg CMG
Product level: 3
PGE: 27
Point of Contact: Andree Jacobson
Senior Application Systems Analyst
MODIS Land Team
Terrestrial Biophysics and Remote Sensing Group (TBRS)
1200 E. South Campus Drive, 429 Shantz Bldg. #38,
Department of Soil, Water and Environmental Science
University of Arizona, Tucson, AZ 85721-0038, USA
Office 520-626-2086; Fax 520-621-1797
Andree@Ag.Arizona.EDU
Principal Investigator: Alfredo Huete
Terrestrial Biophysics and Remote Sensing Group (TBRS)
1200 E South Campus Drive, Room 429, Shantz Bldg. #38,
Department of Soil, Water and Environmental Science,
University of Arizona, Tucson, AZ 85721, USA
Office 520 621 3228; Fax 520 621 5401
ahuete@ag.arizona.edu
Description:
This is the file specification for the 16 day MODIS VI CMG Product. The output
product have datafields for the NDVI, EVI, VI QA, reflectance data, angular
information, and spatial statistics such as mean, standard deviation, and number
of used input pixels at the 0.05 degree CMG resolution. The prodcut is produced
with the MOD13A2 (1km) product as input. Nominally each input consists of 286
tiles which are reprojected into the geographic projection and spatially
averaged and QA filtered. This version of the algorithm works for both Terra
(MOD) and Aqua (MYD) processing, with suitable changes in the pcf files.
Descriptions of metadata attributes and SDSs are given.
Contents:
SDSs always produced:
CMG 0.05 Deg 16 days NDVI
CMG 0.05 Deg 16 days EVI
CMG 0.05 Deg 16 days VI Quality
CMG 0.05 Deg 16 days red reflectance
CMG 0.05 Deg 16 days NIR reflectance
CMG 0.05 Deg 16 days blue reflectance
CMG 0.05 Deg 16 days MIR reflectance
CMG 0.05 Deg 16 days Avg sun zen angle
CMG 0.05 Deg 16 days NDVI std dev
CMG 0.05 Deg 16 days EVI std dev
CMG 0.05 Deg 16 days #1km pix used
CMG 0.05 Deg 16 days #1km pix +-30deg VZ
CMG 0.05 Deg 16 days pixel reliability
ECS Metadata:
CoreMetadata.0
ArchiveMetadata.0
StructMetadata.0
Notes: (A) implies that multiple values are stored within a single array.
A value of "Variable" indicates that this value will vary according to the granule being processed.
"M" mean class M.
Name: Data Type: # values: Source: Value:
------------------------------------------------------------------------------------------------
CoreMetadata.0 PVL-STRING 1 SDPTK Variable
LOCALGRANULEID STRING 1 PGE Variable
SIZEMBECSDATAGRANULE FLOAT 1 DSS Variable
PRODUCTIONDATETIME DATETIME 1 PGE Variable
DAYNIGHTFLAG STRING 1 PGE Variable
REPROCESSINGPLANNED STRING 1 PGE "further update is anticipated"
REPROCESSINGACTUAL STRING 1 PGE "processed once"
LOCALVERSIONID STRING 1 PGE Variable
SCIENCEQUALITYFLAG STRING 1 PGE "Not Investigated"
SCIENCEQUALITYFLAGEXPLANATION STRING 1 PGE "See http://landweb.nascom.nasa.gov/cgi-bin/QA_WWW/qaFlagPage.cgi?sat=aqua for the product Science Quality status"
AUTOMATICQUALITYFLAG STRING 1 PGE "Pass"
AUTOMATICQUALITYFLAGEXPLANATION STRING 1 PGE "No automatic quality assessment is performed in the PGE"
OPERATIONALQUALITYFLAG STRING 1 PGE "being investigated"
OPERATIONALQUALITYFLAGEXPLANATION STRING 1 PGE Variable
QAPERCENTMISSINGDATA INTEGER 1 PGE Variable
QAPERCENTOUTOFBOUNDSDATA INTEGER 1 PGE Variable
QAPERCENTCLOUDCOVER INTEGER 1 PGE Variable
QAPERCENTINTERPOLATEDDATA INTEGER 1 PGE Variable
PARAMETERNAME STRING 1 PGE Variable
VERSIONID STRING 1 MCF "6"
SHORTNAME STRING 1 MCF "MOD13C1"
INPUTPOINTER STRING < 460 PGE Variable (A)
WESTBOUNDINGCOORDINATE DOUBLE 1 PGE -180.0
NORTHBOUNDINGCOORDINATE DOUBLE 1 PGE 90.0
EASTBOUNDINGCOORDINATE DOUBLE 1 PGE 180.0
SOUTHBOUNDINGCOORDINATE DOUBLE 1 PGE -90.0
RANGEBEGINNINGDATE DATE 1 PGE Variable
RANGEBEGINNINGTIME TIME 1 PGE Variable
RANGEENDINGDATE DATE 1 PGE Variable
RANGEENDINGTIME TIME 1 PGE Variable
PGEVERSION STRING 1 PGE "6.0.0" or Variable
ASSOCIATEDSENSORSHORTNAME STRING 1 MCF "MODIS"
ASSOCIATEDPLATFORMSHORTNAME STRING 1 MCF "Aqua"
ASSOCIATEDINSTRUMENTSHORTNAME STRING 1 MCF "MODIS"
**Product Specific Attributes (PSA)**
ADDITIONALATTRIBUTENAME.1 M 1 PGE QAPERCENTGOODQUALITY
PARAMETERVALUE.1 STRING 1 PGE Variable
ADDITIONALATTRIBUTENAME.2 M 1 PGE QAPERCENTOTHERQUALITY
PARAMETERVALUE.2 STRING 1 PGE Variable
ADDITIONALATTRIBUTENAME.3 M 1 PGE QAPERCENTNOTPRODUCEDCLOUD
PARAMETERVALUE.3 STRING 1 PGE Variable
ADDITIONALATTRIBUTENAME.4 M 1 PGE QAPERCENTNOTPRODUCEDOTHER
PARAMETERVALUE.4 STRING 1 PGE Variable
ADDITIONALATTRIBUTENAME.5 M 1 PGE NDVICMG16DAYQCLASSPERCENTAGE
PARAMETERVALUE.5 STRING 1 PGE Variable
ADDITIONALATTRIBUTENAME.6 M 1 PGE EVICMG16DAYQCLASSPERCENTAGE
PARAMETERVALUE.6 STRING 1 PGE Variable
Name: Data Type: # values: Source: Value:
------------------------------------------------------------------------------------------------
ArchiveMetadata.0 PVL-STRING 1 SDPTK Variable
SPSOPARAMETERS STRING 4 MCF "2749", "4334", "2749a", "4334a"
ALGORITHMPACKAGEACCEPTANCEDATE STRING 1 PGE "2004-10-01" (or Variable)
ALGORITHMPACKAGEMATURITYCODE STRING 1 PGE "Normal" (or Variable)
ALGORITHMPACKAGENAME STRING 1 PGE "MOD_PR13C1" (or Variable)
ALGORITHMPACKAGEVERSION STRING 1 PGE "6" (or Variable)
INSTRUMENTNAME STRING 1 MCF "Moderate-Resolution Imaging SpectroRadiometer"
LONGNAME STRING 1 MCF "MODIS/Aqua Vegetation Indices 16-Day L3 Global 0.05 Deg CMG"
PROCESSINGCENTER STRING 1 MCF "MODAPS"
SEAPROCESSED STRING 1 PGE Variable
DESCRrevision STRING 1 PGE Variable
CHARACTERISTICBINANGULARSIZE DOUBLE 1 PGE Variable
CHARACTERISTICBINSIZE DOUBLE 1 PGE Variable
DATACOLUMNS INTEGER 1 PGE Variable
DATAROWS INTEGER 1 PGE Variable
GLOBALGRIDCOLUMNS INTEGER 1 PGE Variable
GLOBALGRIDROWS INTEGER 1 PGE Variable
NUMBEROFDAYS INTEGER 1 PGE Variable
DAYSPROCESSED STRING 16 PGE Variable
GEOANYABNORMAL STRING 1 PGE Variable
GEOESTMAXRMSERROR DOUBLE 1 PGE Variable
QAPERCENTPOORQCMG16DAYNDVI INTEGER 16 PGE Variable
QAPERCENTPOORQCMG16DAYEVI INTEGER 16 PGE Variable
NDVICMG16DAYQCLASSPERCENTAGE INTEGER 1 PGE Variable
EVICMG16DAYQCLASSPERCENTAGE INTEGER 1 PGE Variable
PROCESSINGENVIRONMENT STRING 1 PGE Variable
PERCENTLAND INTEGER 1 PGE Variable
SNOWICEPROCESSED STRING 1 PGE Variable
Name: Data Type: # values: Source: Value:
------------------------------------------------------------------------------------------------
StructuralMetadata.0 PVL-STRING 1 SDPTK Variable
StructMetadata.0: GROUP=SwathStructure
END_GROUP=SwathStructure
GROUP=GridStructure
GROUP=GRID_1
GridName="MODIS_Grid_16Day_VI_CMG"
XDim=7200
YDim=3600
UpperLeftPointMtrs=(-180000000.000000 90000000.000000
LowerRightMtrs=(180000000.000000 -90000000.000000
GridOrigin=HDFE_GD_UL
Projection=GCTP_GEO
GROUP=Dimension
END_GROUP=Dimension
GROUP=DataField
OBJECT=DataField_1
DataFieldName="CMG 0.05 Deg 16 days NDVI"
DataType=DFNT_INT16
DimList=("YDim","XDim")
END_OBJECT=DataField_1
OBJECT=DataField_2
DataFieldName="CMG 0.05 Deg 16 days EVI"
DataType=DFNT_INT16
DimList=("YDim","XDim")
END_OBJECT=DataField_2
OBJECT=DataField_3
DataFieldName="CMG 0.05 Deg 16 days VI Quality"
DataType=DFNT_UINT16
DimList=("YDim","XDim")
END_OBJECT=DataField_3
OBJECT=DataField_4
DataFieldName="CMG 0.05 Deg 16 days red reflectance"
DataType=DFNT_INT16
DimList=("YDim","XDim")
END_OBJECT=DataField_4
OBJECT=DataField_5
DataFieldName="CMG 0.05 Deg 16 days NIR reflectance"
DataType=DFNT_INT16
DimList=("YDim","XDim")
END_OBJECT=DataField_5
OBJECT=DataField_6
DataFieldName="CMG 0.05 Deg 16 days blue reflectance"
DataType=DFNT_INT16
DimList=("YDim","XDim")
END_OBJECT=DataField_6
OBJECT=DataField_7
DataFieldName="CMG 0.05 Deg 16 days MIR reflectance"
DataType=DFNT_INT16
DimList=("YDim","XDim")
END_OBJECT=DataField_7
OBJECT=DataField_8
DataFieldName="CMG 0.05 Deg 16 days Avg sun zen angle"
DataType=DFNT_INT16
DimList=("YDim","XDim")
END_OBJECT=DataField_8
OBJECT=DataField_9
DataFieldName="CMG 0.05 Deg 16 days NDVI std dev"
DataType=DFNT_INT16
DimList=("YDim","XDim")
END_OBJECT=DataField_9
OBJECT=DataField_10
DataFieldName="CMG 0.05 Deg 16 days EVI std dev"
DataType=DFNT_INT16
DimList=("YDim","XDim")
END_OBJECT=DataField_10
OBJECT=DataField_11
DataFieldName="CMG 0.05 Deg 16 days #1km pix used"
DataType=DFNT_UINT8
DimList=("YDim","XDim")
END_OBJECT=DataField_11
OBJECT=DataField_12
DataFieldName="CMG 0.05 Deg 16 days #1km pix +-30deg VZ"
DataType=DFNT_UINT8
DimList=("YDim","XDim")
END_OBJECT=DataField_12
OBJECT=DataField_13
DataFieldName="CMG 0.05 Deg 16 days pixel reliability"
DataType=DFNT_INT8
DimList=("YDim","XDim")
END_OBJECT=DataField_13
END_GROUP=DataField
GROUP=MergedFields
END_GROUP=MergedFields
END_GROUP=GRID_1
END_GROUP=GridStructure
GROUP=PointStructure
END_GROUP=PointStructure
END
Global HDF Attributes
Name: Data Type: # values: Source: Value:
------------------------------------------------------------------------------------------------
HDFEOSVersion STRING 1 SDPTK Variable
End Global Metadata
================================================================================================
SDS Definitions:
Note:
All data stored within DataFields that contain the HDF attributes "scale_factor" and
"add_offset" are scaled according to the following data conversion:
file data = (parameter * scale_factor) + add_offset
parameter = (file data - add_offset) / scale_factor
------------------------------------------------------------------------------------------------
SDS Definition: DataField_1
Name: CMG 0.05 Deg 16 days NDVI
Description: Spatially complete data with cloud filtered and gap filled NDVI values
Data Type: INT16
Rank: 2
Dimension sizes: (3600, 7200)
Dimension Names:
Dimension0: "YDim"
Dimension1: "XDim"
DataField_1 HDF Attributes:
Attribute: Data Type: Number of Values: Source: Value:
long_name STRING string length PGE "CMG 0.05 Deg 16 days NDVI"
units STRING string length PGE "NDVI"
valid_range INT16 2 PGE -2000, 10000
_FillValue INT16 1 PGE -3000
scale_factor FLOAT64 1 PGE 10000.0
scale_factor_err FLOAT64 1 PGE 0.0
add_offset FLOAT64 1 PGE 0.0
add_offset_err FLOAT64 1 PGE 0.0
calibrated_nt INT32 1 PGE 5
------------------------------------------------------------------------------------------------
SDS Definition: DataField_2
Name: CMG 0.05 Deg 16 days EVI
Description: Spatially complete data with cloud filtered and gap filled EVI values
Data Type: INT16
Rank: 2
Dimension Names:
Dimension0: "YDim"
Dimension1: "XDim"
DataField_2 HDF Attributes:
Attribute: Data Type: Number of Values: Source: Value:
long_name STRING string length PGE "CMG 0.05 Deg 16 days EVI"
units STRING string length PGE "EVI"
valid_range INT16 2 PGE -2000, 10000
_FillValue INT16 1 PGE -3000
scale_factor FLOAT64 1 PGE 10000.0
scale_factor_err FLOAT64 1 PGE 0.0
add_offset FLOAT64 1 PGE 0.0
add_offset_err FLOAT64 1 PGE 0.0
calibrated_nt INT32 1 PGE 5
------------------------------------------------------------------------------------------------
SDS Definition: DataField_3
Name: CMG 0.05 Deg 16 days VI Quality
Description: Quality Assurance data for both VI layers defined above. The 16 bit
unsigned integer has been divided into 9 separate QA fields that are
defined below:
Bit: Description:
0-1 NDVI quality
00 NDVI produced, good quality;
01 NDVI produced, but check QA
10 (pixel not produced due to cloud effects)
pixel produced but most likely cloudy
11 pixel not produced due to other reasons than clouds
2-5 VI usefulness
Four bit range where 0 is highest quality, 14 quality too low to be useful,
15 not useful for any other reason (used for fills). The value is calculated
from other QA fields according to the contribution table below.
Parameter Condition Contribution
------------------------------------------------------------
Aerosol Quantity Aerosol level: High 3
Aerosol level: Climatology 2
Aerosol level: Average 1
Adjacent Cloud If detected 2
BRDF Correction If not performed 1
Mixed Clouds If detected 3
Geospatial Quality <=25% contribution 3
<=50% contribution 2
<=75% contribution 1
View Zenith Pixels <50% with +-30deg 2
<100% with +-30deg 1
6-7 aerosol quantity:
climatology (00), low (01), average (10), high (11)
8 Adjacent cloud detected; yes (1) or no (0)
9 yes (1) no (0) atmosphere BRDF correction performed
10 mixed clouds yes (1) no (0)mixed clouds
11-12 land/water flag 00 ocean; 01 coast; 10 wetland; 11 land
13-14 Geospatial quality (Percent contribution)
00 : 25% or less of the finer resolution data contribued to this CMG pixel
01 : 50% or less of the finer resolution data contribued to this CMG pixel
10 : 75% or less of the finer resolution data contribued to this CMG pixel
11 : 100% or less of the finer resolution data contribued to this CMG pixel
15 composite method for NDVI
0 BRDF model based nadir equivalent VI (Currently not used)
1 CVMVC (constraint view angle maximum value VI)
Data Type: UINT16
Rank: 2
Dimension Names:
Dimension0: "YDim"
Dimension1: "XDim"
DataField_3 HDF Attributes:
Attribute: Data Type: Number of Values: Source: Value:
long_name STRING string length PGE "CMG 0.05 Deg 16 days VI Quality"
units STRING string length PGE "bit field"
valid_range INT16 2 PGE 0, 65534
_FillValue INT16 1 PGE 65535
Legend STRING 1553 PGE *Legend similar to above*
------------------------------------------------------------------------------------------------
SDS Definition: DataField_4
Name: CMG 0.05 Deg 16 days red reflectance
Description: QA filtered and spatially averaged red reflectance data
Data Type: INT16
Rank: 2
Dimension Names:
Dimension0: "YDim"
Dimension1: "XDim"
DataField_4 HDF Attributes:
Attribute: Data Type: Number of Values: Source: Value:
long_name STRING string length PGE "CMG 0.05 Deg 16 days red reflectance"
units STRING string length PGE "reflectance"
valid_range INT16 2 PGE 0, 10000
_FillValue INT16 1 PGE -1000
scale_factor FLOAT64 1 PGE 10000.0
scale_factor_err FLOAT64 1 PGE 0.0
add_offset FLOAT64 1 PGE 0.0
add_offset_err FLOAT64 1 PGE 0.0
calibrated_nt INT32 1 PGE 5
------------------------------------------------------------------------------------------------
SDS Definition: DataField_5
Name: CMG 0.05 Deg 16 days NIR reflectance
Description: QA filtered and spatially averaged NIR reflectance data
Data Type: INT16
Rank: 2
Dimension Names:
Dimension0: "YDim"
Dimension1: "XDim"
DataField_5 HDF Attributes:
Attribute: Data Type: Number of Values: Source: Value:
long_name STRING string length PGE "CMG 0.05 Deg 16 days NIR reflectance"
units STRING string length PGE "reflectance"
valid_range INT16 2 PGE 0, 10000
_FillValue INT16 1 PGE -1000
scale_factor FLOAT64 1 PGE 10000.0
scale_factor_err FLOAT64 1 PGE 0.0
add_offset FLOAT64 1 PGE 0.0
add_offset_err FLOAT64 1 PGE 0.0
calibrated_nt INT32 1 PGE 5
------------------------------------------------------------------------------------------------
SDS Definition: DataField_6
Name: CMG 0.05 Deg 16 days blue reflectance
Description: QA filtered and spatially averaged blue reflectance data
Data Type: INT16
Rank: 2
Dimension Names:
Dimension0: "YDim"
Dimension1: "XDim"
DataField_6 HDF Attributes:
Attribute: Data Type: Number of Values: Source: Value:
long_name STRING string length PGE "CMG 0.05 Deg 16 days blue reflectance"
units STRING string length PGE "reflectance"
valid_range INT16 2 PGE 0, 10000
_FillValue INT16 1 PGE -1000
scale_factor FLOAT64 1 PGE 10000.0
scale_factor_err FLOAT64 1 PGE 0.0
add_offset FLOAT64 1 PGE 0.0
add_offset_err FLOAT64 1 PGE 0.0
calibrated_nt INT32 1 PGE 5
------------------------------------------------------------------------------------------------
SDS Definition: DataField_7
Name: CMG 0.05 Deg 16 days MIR reflectance
Description: QA filtered and spatially averaged MIR reflectance data
Data Type: INT16
Rank: 2
Dimension Names:
Dimension0: "YDim"
Dimension1: "XDim"
DataField_7 HDF Attributes:
Attribute: Data Type: Number of Values: Source: Value:
long_name STRING string length PGE "CMG 0.05 Deg 16 days MIR reflectance"
units STRING string length PGE "reflectance"
valid_range INT16 2 PGE 0, 10000
_FillValue INT16 1 PGE -1000
scale_factor FLOAT64 1 PGE 10000.0
scale_factor_err FLOAT64 1 PGE 0.0
add_offset FLOAT64 1 PGE 0.0
add_offset_err FLOAT64 1 PGE 0.0
calibrated_nt INT32 1 PGE 5
------------------------------------------------------------------------------------------------
SDS Definition: DataField_8
Name: CMG 0.05 Deg 16 days Avg sun zen angle
Description: QA filtered and spatially averaged sun zenith angle data
Data Type: INT16
Rank: 2
Dimension Names:
Dimension0: "YDim"
Dimension1: "XDim"
DataField_8 HDF Attributes:
Attribute: Data Type: Number of Values: Source: Value:
long_name STRING string length PGE "CMG 0.05 Deg 16 days Avg sun zen angle"
units STRING string length PGE "degrees"
valid_range INT16 2 PGE -9000, 9000
_FillValue INT16 1 PGE -10000
scale_factor FLOAT64 1 PGE 100.0
scale_factor_err FLOAT64 1 PGE 0.0
add_offset FLOAT64 1 PGE 0.0
add_offset_err FLOAT64 1 PGE 0.0
calibrated_nt INT32 1 PGE 5
------------------------------------------------------------------------------------------------
SDS Definition: DataField_9
Name: CMG 0.05 Deg 16 days NDVI std dev
Description: Standard deviation computed from input NDVI pixels that passed QA filtering
Data Type: INT16
Rank: 2
Dimension Names:
Dimension0: "YDim"
Dimension1: "XDim"
DataField_9 HDF Attributes:
Attribute: Data Type: Number of Values: Source: Value:
long_name STRING string length PGE "CMG 0.05 Deg 16 days NDVI std dev"
units STRING string length PGE "NDVI"
valid_range INT16 2 PGE 0, 10000
_FillValue INT16 1 PGE -3000
scale_factor FLOAT64 1 PGE 10000.0
scale_factor_err FLOAT64 1 PGE 0.0
add_offset FLOAT64 1 PGE 0.0
add_offset_err FLOAT64 1 PGE 0.0
calibrated_nt INT32 1 PGE 5
------------------------------------------------------------------------------------------------
SDS Definition: DataField_10
Name: CMG 0.05 Deg 16 days EVI std dev
Description: Standard deviation computed from input EVI pixels that passed QA filtering
Data Type: INT16
Rank: 2
Dimension Names:
Dimension0: "YDim"
Dimension1: "XDim"
DataField_10 HDF Attributes:
Attribute: Data Type: Number of Values: Source: Value:
long_name STRING string length PGE "CMG 0.05 Deg 16 days EVI std dev"
units STRING string length PGE "EVI"
valid_range INT16 2 PGE 0, 10000
_FillValue INT16 1 PGE -3000
scale_factor FLOAT64 1 PGE 10000.0
scale_factor_err FLOAT64 1 PGE 0.0
add_offset FLOAT64 1 PGE 0.0
add_offset_err FLOAT64 1 PGE 0.0
calibrated_nt INT32 1 PGE 5
------------------------------------------------------------------------------------------------
SDS Definition: DataField_11
Name: CMG 0.05 Deg 16 days #1km pix used
Description: The number of 1km input pixels that passed the QA filter and were used for
calculation of the resulting CMG pixel. Will be set to 0 if no pixels were
used. This is also true for pixels in boreal darkness. The layer is complete
and was constructed by referring to the ancillary input landwater mask.
Data Type: UINT8
Rank: 2
Dimension Names:
Dimension0: "YDim"
Dimension1: "XDim"
DataField_11 HDF Attributes:
Attribute: Data Type: Number of Values: Source: Value:
long_name STRING string length PGE "CMG 0.05 Deg 16 days #1km pix used"
units STRING string length PGE "Pixels"
valid_range INT16 2 PGE 0, 36
_FillValue INT16 1 PGE 255
scale_factor FLOAT64 1 PGE 1.0
scale_factor_err FLOAT64 1 PGE 0.0
add_offset FLOAT64 1 PGE 0.0
add_offset_err FLOAT64 1 PGE 0.0
calibrated_nt INT32 1 PGE 5
------------------------------------------------------------------------------------------------
SDS Definition: DataField_12
Name: CMG 0.05 Deg 16 days #1km pix +-30deg VZ
Description: The number of 1km input pixels that passed the QA filter and had a view
zenith angle less than +/-30 degrees in the input data. This number will
always be less than or equal to the number defined in SDS #11 above.
Data Type: UINT8
Rank: 2
Dimension Names:
Dimension0: "YDim"
Dimension1: "XDim"
DataField_12 HDF Attributes:
Attribute: Data Type: Number of Values: Source: Value:
long_name STRING string length PGE "CMG 0.05 Deg 16 days #1km pix +-30deg VZ"
units STRING string length PGE "Pixels"
valid_range INT16 2 PGE 0, 36
_FillValue INT16 1 PGE 255
scale_factor FLOAT64 1 PGE 1.0
scale_factor_err FLOAT64 1 PGE 0.0
add_offset FLOAT64 1 PGE 0.0
add_offset_err FLOAT64 1 PGE 0.0
calibrated_nt INT32 1 PGE 5
------------------------------------------------------------------------------------------------
SDS Definition: DataField_13
Name: CMG 0.05 Deg 16 days pixel reliability
Description: The CMG pixel realiability is a ranking scheme that summarizes all QA
info indicating how reliable the pixel is:
-1 : No data, FILL value
0 : Ideal data, use with confidence
1 : Good data, but with one or more problems of aerosol, shadow, viewing
geomtery, etc..
2 : Possible snow/ice cover (only set if requested in the PCF).
The algorithm uses a threshold technique based on the input QA snow/
ice flag. If 10% or more of contributing input pixels to a CMG pixel
have the snow/ice flag set, it will be marked as snow/ice. In case
the PCF flag is set to NO, no information regarding snow/ice cover
will be present in the output. There is a metadata attribute in the
output file, "SNOWICEFLAGGED", that indicates whether or not snow/ice
was flagged at processing time.
3 : Cloud covered data
Theoretically there should be no cloudy data in this product. The
algorithm completely filters all cloudy data and fill the gaps using
historic MODIS time series data set. However, when no historic data is
available (<0.002% of all pixels, collection 4 icorrectly marked data),
the VI layers will display a fill calculated from cloudy values and
this will be indicated in the pixel reliability.
4 : No real data, estimaetd from historic time series(*)
(*) The historic time series used to fill the gaps is a compilation of a consistent
year average from all the MODIS data to this date. This historic data set is
only used when actual data is missing or cloudy for the composite periods being
processed.
Data Type: INT8
Rank: 2
Dimension Names:
Dimension0: "YDim"
Dimension1: "XDim"
DataField_13 HDF Attributes:
Attribute: Data Type: Number of Values: Source: Value:
long_name STRING string length PGE "CMG 0.05 Deg 16 days pixel reliability"
units STRING string length PGE "rank"
valid_range INT16 2 PGE 0, 4
_FillValue INT16 1 PGE -1
scale_factor FLOAT64 1 PGE 1.0
scale_factor_err FLOAT64 1 PGE 0.0
add_offset FLOAT64 1 PGE 0.0
add_offset_err FLOAT64 1 PGE 0.0
calibrated_nt INT32 1 PGE 5
------------------------------------------------------------------------------------------------