HDF-EOS V2 MODIS L2G Thermal Bands File Specification
Revision 1.0 (06/01/05)
Product ID(s): MODIS Thermal Band L2G Daily 1km Night (MODTBGN)
NOTE: Currently cannot be made since thermal bands are read from
MOD09 and MOD09 granules are made only for day granules.
Description:
The MODIS 1km Resolution Level 2G (L2G) Thermal Band file contains the
restructured Level 2 (L2) thermal band data from band 20, 31 and 32 which
intersects a geographic area, a tile in the Level 3 (L3) grid. The actual
data stored is based on a set of pointers to observations which intersect
each cell (pixel) in the corresponding L2G 1km Observation Pointer file. A
single 1km thermal band observation consist of observations from
Bands 20, 31, and 32. Nominally, a entire data-day's (24 hours GMT) worth
of data, which intersects the tile, is stored in the file. L2 thermal bands
observations are read from L2 MOD09 product.
The global L3 grid is divided into a number of tiles, areas with a nominal
size of 1100 km by 1100 km (10 deg. by 10 deg.).
For each pixel in the output tile, the 1km observation pointer is used to
find the location of the spatial element in each of the L2 product files
The value for each observation is extracted from the corresponding locations
in the L2 file. A one-to-one correspondence is kept between the
information in the observation pointer file and the surface reflectance file.
One additional data set is stored in the output file, the orbit and
coverage data set. The orbit number and scan half field are intended to be
used to allow a user to find the corresponding geolocation angle
information for a given observation. The observation coverage field gives
a coarse estimate of the area of intersection between the observation and
the cell (relative to the observation area). Both of these fields are
primarily meant to be used in the absence of the corresponding observation
pointer files.
There are two ways to which the observation data can be stored in a L2G
grid file, full and compact. The actual method is specified by the
L2GStorageFormat metadatum. In both methods, the first layer of
observations is stored in a 2 dimensional array. In the full method,
all of the values are stored in a 3 dimensional array with the slowest
varying dimension specifying the observation layer. This is an inefficient
storage method because typically a large number of cells are empty. For
the compact method, the additional observation values are stored in a single
dimensional array, with the dimension corresponding to the number of
additional observations since the beginning of the file. Essentially, the
additional observations are run-length encoded with each observation stored
sequentially for each cell. Only the full format is meant for distribution.
In addition, for initial production after launch, the user may specify that
only the first layer be stored, in which case the additional arrays are not
stored.
Point of Contact:
Sadashiva Devadiga
(301) 614-5449
Kai Yang
Science Systems and Applications Inc.
NASA's Goddard Space Flight Center, Code 922
Greenbelt, MD 20771
(301) 614-5452
kyang@ltpmail.gsfc.nasa.gov
Robert Wolfe
Hughes STX
NASA's Goddard Space Flight Center, Code 922
Greenbelt, MD 20771
(301) 614-5508
robert.wolfe@gsfc.nasa.gov
Principal Investigator:
Eric Vermote
University of Maryland, College Park
NASA's Goddard Space Flight Center, Code 923
Greenbelt, MD 20771
(301) 286-6232
vermote@kratmos.gsfc.nasa.gov
===========================================================================
Generic Constructs
ECS Metadata Strings:
Notes: "FR" is an abbreviation for "FREE_RANGE".
"D/T" is an abbreviation for "DATE/TIME"
(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" means class M.
CoreMetadata.0
This string will contain the following PVL fields:
# of
Field Name Data Value Value
Type s
GROUP = INVENTORYMETADATA
GROUP = CollectionDescriptionClass
SHORTNAME STRING 1 "MODTBGD"
VERSIONID STRING 1 Variable
END_GROUP = CollectionDescriptionClass
GROUP = ECSDataGranule
REPROCESSINGPLANNED STRING 1 "no further update
anticipated"
REPROCESSINGACTUAL STRING 1 "processed once"
LOCALGRANULEID STRING 1 Variable
DAYNIGHTFLAG STRING 1 Variable
PRODUCTIONDATETIME D/T 1 Variable
LOCALVERSIONID STRING 1 Variable
SIZEMBECSDATAGRANULE FLOAT 1 Variable
END_GROUP = ECSDataGranule
GROUP = PGEVersionClass
PGEVERSION STRING 1 "5.0.0"
END_GROUP = PGEVersionClass
GROUP = InputGranule
INPUTPOINTER STRING FR (A) Variable
END_GROUP = InputGranule
GROUP = RangeDateTime
RANGEBEGINNINGDATE DATE 1 Variable
RANGEBEGINNINGTIME TIME 1 Variable
RANGEENDINGDATE DATE 1 Variable
RANGEENDINGTIME TIME 1 Variable
END_GROUP = RangeDateTime
GROUP = GRing
EXCLUSIONGRINGFLAG STRING 1 "N"
END_GROUP = GRing
GROUP = GRingPoint
GRINGPOINTLATITUDE DOUBLE 4 (A) Variable
GRINGPOINTLONGITUDE DOUBLE 4 (A) Variable
GRINGPOINTSEQUENCENO INTEGER 4 (A) Variable
END_GROUP = GRingPoint
GROUP = OrbitCalculatedSpatialDomain
ORBITNUMBER INTEGER "NumberofGranules"
Variable
EQUATORCROSSINGLONGITUDE DOUBLE "NumberofGranules"
Variable
EQUATORCROSSINGDATE DATE "NumberofGranules"
Variable
EQUATORCROSSINGTIME TIME "NumberofGranules"
Variable
END_GROUP = OrbitCalculatedSpatialDomain
GROUP = MeasuredParameter
PARAMETERNAME STRING FR (A) Variable
GROUP = QAFlags
AUTOMATICQUALITYFLAG STRING 1 Variable
AUTOMATICQUALITYFLAGEXPLANATION
STRING 1 Variable
OPERATIONALQUALITYFLAG STRING 1 Variable
OPERATIONALQUALITYFLAGEXPLANATION
STRING 1 Variable
SCIENCEQUALITYFLAG STRING 1 Variable
SCIENCEQUALITYFLAGEXPLANATION
STRING 1 Variable
END_GROUP = QAFlags
GROUP = QAStats
QAPERCENTMISSINGDATA INTEGER 1 Variable
END_GROUP = QAStats
END_GROUP = MeasuredParameter
******************************************************************
* Note that MeasuredParameter group has
* Class = "M" (see sample MCF file).
* Basically one needs to put DataField (SDS) names to PARAMETERNAME
* and put corresponding QA metadata to QAFlags and QAStats.
* If one has only QA metadata for whole product, instead for each
* and individual DatFiels (SDS), it's suggested to put product
* name to PARAMETERNAME.
*******************************************************************
GROUP = AssociatedPlatformInstrumentSensor
ASSOCIATEDPLATFORMSHORTNAME STRING 1 "AM-1"
ASSOCIATEDINSTRUMENTSHORTNAME STRING 1 "MODIS"
ASSOCIATEDSENSORSHORTNAME STRING 1 "CCD"
END_GROUP = AssociatedPlatformInstrumentSensor
GROUP = AdditionalAttributes
ADDITIONALATTRIBUTENAME STRING FR (A) Variable
PARAMETERVALUE STRING FR (A) Variable
ADDITIONALATTRIBUTENAME.1 = "QAPERCENTGOODQUALITY"
ADDITIONALATTRIBUTENAME.2 = "QAPERCENTOTHERQUALITY"
ADDITIONALATTRIBUTENAME.3 = "QAPERCENTNOTPRODUCEDCLOUD"
ADDITIONALATTRIBUTENAME.4 = "QAPERCENTNOTPRODUCEDOTHER"
ADDITIONALATTRIBUTENAME.5 = "HORIZONTALTILENUMBER"
ADDITIONALATTRIBUTENAME.6 = "VERTICALTILENUMBER"
ADDITIONALATTRIBUTENAME.7 = "TileID"
ADDITIONALATTRIBUTENAME.8 = "QAPERCENTPOOROUTPUT500MBAND3"
ADDITIONALATTRIBUTENAME.9 = "QAPERCENTPOOROUTPUT500MBAND4"
ADDITIONALATTRIBUTENAME.10 = "QAPERCENTPOOROUTPUT500MBAND5"
ADDITIONALATTRIBUTENAME.11 = "QAPERCENTPOOROUTPUT500MBAND6"
ADDITIONALATTRIBUTENAME.12 = "QAPERCENTPOOROUTPUT500MBAND7"
*******************************************************
* Other SCF defined PSA attributes:
*******************************************************
END_GROUP = AdditionalAttributes
END_GROUP = INVENTORYMETADATA
ArchiveMetadata.0
This string will contain the following PVL fields:
# of
Field Name Data Value Value
Type s
GROUP = ARCHIVEMETADATA
GROUP = BoundingRectangle
WESTBOUNDINGCOORDINATE DOUBLE 1 Variable
NORTHBOUNDINGCOORDINATE DOUBLE 1 Variable
EASTBOUNDINGCOORDINATE DOUBLE 1 Variable
SOUTHBOUNDINGCOORDINATE DOUBLE 1 Variable
END_GROUP = BoundingRectangle
ALGORITHMPACKAGEACCEPTANCEDATE
STRING 1 "TBD"
ALGORITHMPACKAGEMATURITYCODE STRING 1 "Preliminary"
ALGORITHMPACKAGENAME STRING 1 "MOD_PRMGR"
ALGORITHMPACKAGEVERSION STRING 1 "2.1"
GEOANYABNORMAL STRING 1 Variable
GEOESTMAXRMSERROR DOUBLE 1 Variable
LONGNAME STRING 1 "MODIS/Terra Thermal Bands Daily L2G Global 1km SIN Grid Night"
SPSOPARAMETERS STRING 1 Variable
PROCESSINGCENTER STRING 1 "GSFC"
NUMBEROFOVERLAPGRANULES INTEGER 1 Variable
NUMBEROFINPUTGRANULES INTEGER 1 Variable
GRANULENUMBERARRAY INTEGER "NumberofGranules"
Variable
ORBITNUMBERARRAY INTEGER "NumberofGranules"
Variable
GRANULEBEGINNINGDATETIME STRING "NumberofGranules"
Variable
GRANULEENDINGDATETIME STRING "NumberofGranules"
Variable
GRANULEDAYNIGHTFLAG STRING "NumberofGranules"
Variable
MINIMUMLINEINDEX INTEGER "NumberofGranules"
Variable
MAXIMUMLINEINDEX INTEGER "NumberofGranules"
Variable
MINIMUMSAMPLEINDEX INTEGER "NumberofGranules"
Variable
MAXIMUMSAMPLEINDEX INTEGER "NumberofGranules"
Variable
GRANULEPOINTERARRAY INTEGER "NumberofGranules"
Variable
NADIRDATARESOLUTION STRING 1 Variable
CHARACTERISTICBINANGULARSIZE DOUBLE 1 Variable
CHARACTERISTICBINSIZE DOUBLE 1 Variable
DATACOLUMNS INTEGER 1 Variable
DATAROWS INTEGER 1 Variable
GLOBALGRIDCOLUMNS INTEGER 1 Variable
GLOBALGRIDROWS INTEGER 1 Variable
MAXIMUMOBSERVATIONS INTEGER 1 Variable
ADDITIONALLAYERS INTEGER 1 Variable
TOTALOBSERVATIONS INTEGER 1 Variable
TOTALADDITIONALOBSERVATIONS INTEGER 1 Variable
COVERAGECALCULATIONMETHOD STRING 1 Variable
FIRSTLAYERSELECTIONCRITERIA STRING 1 Variable
L2GSTORAGEFORMAT STRING 1 Variable
REFERENCEORBITNUMBER INTEGER 1 Variable
******************************************************************
* 1. The field "L2GStorageFormat" is either "full",
* "compact" or "one layer only".
* 2. The field "CoverageCalculationMethod" is either
* "area" or "simple PSF".
* 3. The field "FirstLayerSelectionCriteria" is either
* "nearest neighbor" or "maximum observation coverage".
******************************************************************
END_GROUP = ARCHIVEMETADATA
StructuralMetadata.0
This string will be populated automatically by HDF-EOS.
Grid Structure: MOD_Grid_L2g_2d
Dimensions:
Dimension Name Value
YDim:MOD_Grid_L2g_2d "Data Rows"
XDim:MOD_Grid_L2g_2d "Data Columns"
Corner Locations:
Corner Values
UpperLeftPointMtrs (Variable, Variable)
LowerRightPointMtrs (Variable, Variable)
Geographic Grid Projection Parameters:
Note that all grid parameters are currently under development
and may need to be revised prior to V2.0 code delivery.
Supported Grids: Integerized Sinusoidal (GCTP_ISINUS)
Interrupted Goodes Homolosine (GCTP_GOOD)
Lambert Azimuthal Equal Area (GCTP_LAMAZ)
Projection gridID = GCTP_ISINUS
ProjParam[0] 6371007.181
ProjParam[1 to 7] 0.0
ProjParam[8] 86400
ProjParam[9] 0.0
ProjParam[10] 1.0
ProjParam[11 to 12] 0.0
Spherecode -1
GridOrigin HDFE_GD_UL
Projection gridID = GCTP_GOOD
ProjParam[0 to 12] 0.0
Spherecode 19
GridOrigin HDFE_GD_UL
Projection gridID = GCTP_LAMAZ
ProjParam[0] 6371228.0
ProjParam[1 to 5] 0.0
ProjParam[6] Variable
ProjParam[7 to 12] 0.0
Spherecode 19
GridOrigin HDFE_GD_UL
Grid Structure: MOD_Grid_L2g_3d
Dimensions:
Dimension Name Value
Additional Layers:MOD_Grid_L2g_3d "Additional Layers"
YDim:MOD_Grid_L2g_3d "Data Rows"
XDim:MOD_Grid_L2g_3d "Data Columns"
Corner Locations: (same as MOD_Grid_L2g_2d)
Geographic Grid Projection: (same as MOD_Grid_L2g_2d)
===========================================================================
DataFields:
The following datafields are always in this file:
num_observations
BAND20_1
BAND31_1
BAND32_1
orb_cov_1
If the metadatum "L2GStorageFormat" is "full", the following
datafields are also present:
BAND20_f
BAND31_f
BAND32_f
orb_cov_f
If the metadatum "L2GStorageFormat" is "compact", the following
datafields are also present:
BAND20_c
BAND31_c
BAND32_c
orb_cov_c
nadd_obs_row
Each datafield has at least the following 4 attributes:
long_name (STRING)
units (STRING)
valid_range (agrees with data type of SDS)
_FillValue (agrees with data type of SDS)
Some datafields also contain the following 5 attributes:
add_offset (float64)
add_offset_err (float64)
calibrated_nt (int32)
scale_factor (float64)
scale_factor_err (float64)
Nadir Data Resolution (STRING)
===========================================================================
Name Data Dimensions
Type
num_observations INT8 "YDim:MOD_Grid_L2g_2d",
"XDim:MOD_Grid_L2g_2d"
Description:
The number of observations per pixel contained within
this L2G file. In addition, if the value is less than zero,
it means that intersections were not computed for this cell.
If it is -1, it is part of the fill region of the grid. If it
is -2, it is in the area identified as 'non-production' in the
Land Production Mask.
HDF Attributes:
Number of
Values or
Max.
Attribute Data String Value
Type Length
long_name STRING 22 Number of observations
units STRING 4 none
valid_range INT8 2 0, 127
_FillValue INT8 1 -1
===========================================================================
Name Data Dimensions
Type
BAND20_1 UINT16 "YDim:MOD_Grid_L2g_2d",
"XDim:MOD_Grid_L2g_2d"
BAND20_f UINT16 "Additional Layers:MOD_Grid_L2g_3d",
"YDim:MOD_Grid_L2g_3d",
"XDim:MOD_Grid_L2g_3d"
BAND20_c UINT16 metadatum "TotalAdditionalObservations"
Description:
MODIS Thermal Band 20.
"BAND20_1" is for storing the first layer of observations
and is always stored.
"BAND20_f" and "BAND20_c" are for storing the
additional layers of observations. "BAND20_f" is for the
full format and is stored only if the metadatum
"L2GStorageFormat" is "full". "BAND20_c" is for the
compact format and is stored only if the metadatum
"L2GStorageFormat" is "compact".
HDF Attributes:
Number of
Values or
Max.
Attribute Data String Value
Type Length
long_name STRING 60 Variable
units STRING 11 K
valid_range INT16 2 0, 32236
_FillValue INT16 1 0
Nadir Data Resolution
STRING 4 1km
scale_factor FLOAT64 1 100
add_offset FLOAT64 1 0
scale_factor_err FLOAT64 1 0
add_offset_err FLOAT64 1 0
calibrated_nt INT32 1 5
Note: The attribute "long_name" is "1km Band 20 Brightness Temperature - first layer"
for "BAND20_1", "1km Band 20 Brightness Temperature - additional layers, full"
for "BAND20_f" or "1km Band 20 Brightness Temperature - additional layers, compact"
for "BAND20_c".
===========================================================================
Name Data Dimensions
Type
BAND31_1 UINT16 "YDim:MOD_Grid_L2g_2d",
"XDim:MOD_Grid_L2g_2d"
BAND31_f UINT16 "Additional Layers:MOD_Grid_L2g_3d",
"YDim:MOD_Grid_L2g_3d",
"XDim:MOD_Grid_L2g_3d"
BAND31_c UINT16 metadatum "TotalAdditionalObservations"
Description:
MODIS Thermal Band 31.
"BAND31_1" is for storing the first layer of observations
and is always stored.
"BAND31_f" and "BAND31_c" are for storing the
additional layers of observations. "BAND31_f" is for the
full format and is stored only if the metadatum
"L2GStorageFormat" is "full". "BAND31_c" is for the
compact format and is stored only if the metadatum
"L2GStorageFormat" is "compact".
HDF Attributes:
Number of
Values or
Max.
Attribute Data String Value
Type Length
long_name STRING 60 Variable
units STRING 11 K
valid_range INT16 2 0, 32236
_FillValue INT16 1 0
Nadir Data Resolution
STRING 4 1km
scale_factor FLOAT64 1 100
add_offset FLOAT64 1 0
scale_factor_err FLOAT64 1 0
add_offset_err FLOAT64 1 0
calibrated_nt INT32 1 5
Note: The attribute "long_name" is "1km Band 31 Brightness Temperature - first layer"
for "BAND31_1", "1km Band 31 Brightness Temperature - additional layers, full"
for "BAND31_f" or "1km Band 31 Brightness Temperature - additional layers, compact"
for "BAND31_c".
===========================================================================
Name Data Dimensions
Type
BAND32_1 UINT16 "YDim:MOD_Grid_L2g_2d",
"XDim:MOD_Grid_L2g_2d"
BAND32_f UINT16 "Additional Layers:MOD_Grid_L2g_3d",
"YDim:MOD_Grid_L2g_3d",
"XDim:MOD_Grid_L2g_3d"
BAND32_c UINT16 metadatum "TotalAdditionalObservations"
Description:
MODIS Thermal Band 32.
"BAND32_1" is for storing the first layer of observations
and is always stored.
"BAND32_f" and "BAND32_c" are for storing the
additional layers of observations. "BAND32_f" is for the
full format and is stored only if the metadatum
"L2GStorageFormat" is "full". "BAND32_c" is for the
compact format and is stored only if the metadatum
"L2GStorageFormat" is "compact".
HDF Attributes:
Number of
Values or
Max.
Attribute Data String Value
Type Length
long_name STRING 60 Variable
units STRING 11 K
valid_range INT16 2 0, 32236
_FillValue INT16 1 0
Nadir Data Resolution
STRING 4 1km
scale_factor FLOAT64 1 100
add_offset FLOAT64 1 0
scale_factor_err FLOAT64 1 0
add_offset_err FLOAT64 1 0
calibrated_nt INT32 1 5
Note: The attribute "long_name" is "1km Band 32 Brightness Temperature - first layer"
for "BAND32_1", "1km Band 32 Brightness Temperature - additional layers, full"
for "BAND32_f" or "1km Band 32 Brightness Temperature - additional layers, compact"
for "BAND32_c".
===========================================================================
Name Data Dimensions
Type
orb_cov_1 UINT8 "YDim:MOD_Grid_L2g_2d",
"XDim:MOD_Grid_L2g_2d"
orb_cov_f UINT8 "Additional Layers:MOD_Grid_L2g_3d",
"YDim:MOD_Grid_L2g_3d",
"XDim:MOD_Grid_L2g_3d"
orb_cov_c UINT8 metadatum "TotalAdditionalObservations"
Description:
Orbit and coverage: the orbit the observation came from and
the observation coverage. The orbit number is not the absolute
orbit number but a relative orbit number in the file. In
addition a flag is stored which distinguishes between
observations which are in the top half of the scan (the first
5 1km scan lines in the along track direction) and the bottom
half of the scan (the last 5 1km scan lines). The observation
coverage is the area of intersection of observation footprint
and cell divided by the area of the observation.
Bit Description
0-3 Orbit number: 4 bit unsigned integer; range 0 to 13
key: 0000 ( 0) to 1011 (13)
4 Scan half flag; which half of the scan the observation
came from:
key: 0 - top half
1 - bottom half
5-7 Observation coverage: 3 bit unsigned integer;
range 0 to 7
key: 000 (0) - 0.0 to 12.5%
001 (1) - 12.5 to 25.0%
010 (2) - 25.0 to 37.5%
011 (3) - 37.5 to 50.0%
100 (4) - 50.0 to 62.5%
101 (5) - 62.5 to 75.0%
110 (6) - 75.0 to 87.5%
111 (7) - 87.5 to 100.0%
"orb_cov_1" is for storing the first layer of observations
and is always stored.
"orb_cov_f" and "orb_cov_c" are for storing the
additional layers of observations. "orb_cov_f" is for the
full format and is stored only if the metadatum
"L2GStorageFormat" is "full". "orb_cov_c" is for the
compact format and is stored only if the metadatum
"L2GStorageFormat" is "compact".
HDF Attributes:
Number of
Values or
Max.
Attribute Data String Value
Type Length
long_name STRING 49 Variable
units STRING 9 bit field
valid_range UINT8 2 0, 255
_FillValue UINT8 1 15
Note: The attribute "long_name" is "Orbit and coverage
- first layer" for "orb_cov_1", "Orbit and coverage -
additional layers, full" for "orb_cov_f", or "Orbit and
coverage - additional layers, compact" for "orb_cov_c".
===========================================================================
Name Data Dimensions
Type
nadd_obs_row INT32 metadatum "DataRows"
Description:
The number of additional observations in each row in the
compact storage form of the L2G grid.
This field is only stored if the metadatum "L2GStorageFormat"
is "compact".
HDF Attributes:
Number of
Values or
Max.
Attribute Data String Value
Type Length
long_name STRING 41 Number of additional
observations per row
units STRING 4 none
valid_range INT32 2 0, INT32_MAX
_FillValue INT32 1 -1
=========================================================================