MODIS L2 Fire Version 6 File Specification
Revision 6.2.3, 4 September 2014
This document specifies the format for the Terra MODIS Level 2 Active
Fire product (MOD14).
Point of Contact:
Louis Giglio (PI)
University of Maryland
Department of Geographical Sciences
College Park, MD 20742
(301) 405-0064
lgiglio@umd.edu
Chris Justice (Co-I)
Department of Geographical Sciences
University of Maryland
College Park, MD 20742
(301) 405-0064
cjustice@umd.edu
1. ECS Granule Metadata
1.1 CoreMetadata.0
ECS Core metadata are inconveniently stored in a single HDF attribute as a
large string of PVL text.
Name ECS Type
---- --------
LocalGranuleID string
SizeMBECSDataGranule double
ProductionDateTime DATETIME
DayNightFlag string
ReprocessingActual string
ReprocessingPlanned string
LocalVersionID string
ScienceQualityFlag string
AutomaticQualityFlagExplanation string
AutomaticQualityFlag string
OperationalQualityFlagExplanation string
OperationalQualityFlag string
ScienceQualityFlagExplanation string
QAPercentMissingData integer
EquatorCrossingDate DATE
EquatorCrossingTime TIME
OrbitNumber integer
EquatorCrossingLongitude double
VersionID integer
ShortName string
GRingPointLongitude double
GRingPointLatitude double
GRingPointSequenceNo integer
ExclusionGRingFlag string
RangeEndingDate DATE
RangeEndingTime TIME
RangeBeginningDate DATE
RangeBeginningTime TIME
InputGranule string
InputPointer string
PGEVersion string
AncillaryInputPointer string
AncillaryInputType string
AssociatedSensorShortName string
AssociatedPlatformShortName string
AssociatedInstrumentShortName string
The following will be the AdditionalAttributes set:
AdditionalAttribute.1 = QAPERCENTGOODQUALITY (integer)
AdditionalAttribute.2 = QAPERCENTOTHERQUALITY (integer)
AdditionalAttribute.3 = QAPERCENTNOTPRODUCEDCLOUD (integer)
AdditionalAttribute.4 = QAPERCENTNOTPRODUCEDOTHER (integer)
AdditionalAttribute.5 = FirePixels (integer)
AdditionalAttribute.6 = GRANULENUMBER (integer)
AdditionalAttribute.7 = PROCESSVERSION (string)
1.2 ArchiveMetadata.0
ECS Archive metadata are also inconveniently stored in a single HDF
attribute as a large string of PVL text.
Name ECS Type
---- --------
AlgorithmPackageAcceptanceDate string
AlgorithmPackageMaturityCode string
AlgorithmPackageName string
AlgorithmPackageVersion string
SystemFileName string
AncillarySystemFileName string
LongName string
ProcessingCenter string
SPSOParameters string
NorthBoundingCoordinate double
SouthBoundingCoordinate double
EastBoundingCoordinate double
WestBoundingCoordinate double
InstrumentScansProcessed integer
PercentLand integer
scistate integer
sciabnorm integer
CloudPixels integer
NoFirePixels integer
GlintPixels integer
UnknownPixels integer
WaterPixels integer
CloudAdjacentFirePixels integer
WaterAdjacentFirePixels integer
InternalCloudMask string
DESCRrevision string
ProductionHistory string
ProcessingEnvironment string
2. Product-Specific Granule Metadata
The following fields are stored as individual HDF attributes. Many are
duplicates of the ECS Core and Archive metadata fields to prevent users from
having to parse metadata stored in the confusing PVL format mandated by the
ECS.
Name Type Description
---- ---- -----------
FirePix int32 Total number of fire pixels detected in granule.
LandFirePix int32 Number of fire pixels detected over land in
granule.
WaterFirePix int32 Number of fire pixels detected over water in
granule.
MissingPix int32 Number of pixels classified as "missing"
in granule.
LandPix int32 Number of land pixels in granule.
WaterPix int32 Number of water pixels in granule.
CoastPix int32 Number of coast pixels in granule.
WaterAdjacentFirePix int32 Number of fire pixels having one or more
adjacent water pixels.
CloudAdjacentFirePix int32 Number of fire pixels having one or more
adjacent cloud pixels.
UnknownLandPix int32 Number of land pixels classified as "unknown"
in granule.
UnknownWaterPix int32 Number of water pixels classified as "unknown"
in granule.
LandCloudPix int32 Number of cloud pixels over land in granule.
WaterCloudPix int32 Number of cloud pixels over water in granule.
GlintPix int32 Number of pixels in sun glint region.
GlintRejectedPix int32 Number of apparent fire pixels rejected as
false alarms caused by sun-glint.
CoastRejectedLandPix int32 Number of apparent land fire pixels rejected as
coastal false alarms.
HotSurfRejectedPix int32 Number of apparent land fire pixels rejected as
desert-boundary false alarms.
ClearingRejectedPix int32 Number of apparent land fire pixels rejected as
false alarms caused by small forest clearings.
CoastRejectedWaterPix int32 Number of apparent water fire pixels rejected
as unmasked land- or coast-pixel false alarms.
DayPix int32 Number of daytime pixels in granule.
NightPix int32 Number of nighttime pixels in granule.
MissingRadPix int32 Number of pixels having missing radiance
values in one or more bands used by algorithm.
MissingGeoPix int32 Number of pixels having missing geolocation
data.
Satellite string "Terra"
ProcessVersionNumber string Internal version number (e.g. "6.1.0").
MOD021KM input file string 1 km L1B input file name.
MOD03 input file string Geolocation input file name.
SystemID string Unix/Linux system information
3. HDF Dimension Names
Dimension Name Value
--------- ---- -----
Dimension_1 Number_of_scan_lines # of input scan lines * 10
Dimension_2 Pixels_per_scan_line 1354
Dimension_3 Number_of_active_fires # of active fires detected
Dimension_4 cmg_cells_day # of CMG cells covered by swath
Dimension_5 cmg_cells_night # of CMG cells covered by swath
Dimension_6 cmg_values 8
4. Scientific Data Sets
All data stored within the following two-dimensional Scientific Data Sets
are Level 2 granules, and correspond on a pixel-to-pixel basis with other
1-km Level 2 granules generated by other MODIS PGEs.
Name Type Dimensions
---- ---- ----------
fire mask uint8 Dimension_1, Dimension_2
SDS Attributes:
Attribute Type Quantity Value
--------- ---- -------- -----
long_name string 1 fire mask
Nadir Data Resolution string 1 1 km
valid_range uint8 2 0, 9
_FillValue uint8 1 0
Value Description
----- -----------
0 not processed (missing input data)
1 not processed (obsolete; not used in post-launch product)
2 not processed (other reason)
3 non-fire water pixel
4 cloud (land or water)
5 non-fire land pixel
6 unknown (land or water)
7 fire (low confidence, land or water)
8 fire (nominal confidence, land or water)
9 fire (high confidence, land or water)
-----------------------------------------------------------------------------
Name Type Dimensions
---- ---- ----------
algorithm QA uint32 Dimension_1, Dimension_2
SDS Attributes:
Attribute Type Quantity Value
--------- ---- -------- -----
long_name string 1 algorithm QA
units string 1 bit field
Nadir Data Resolution string 1 1 km
Bit Description
--- -----------
0-1 land/water state
00 = water
01 = coast
10 = land
11 = UNUSED
2 3.9 micron high-gain flag
0 = band 21 used
1 = band 22 used
3 atmospheric correction (0 = not performed, 1 = performed)
4 day/night algorithm (0 = night, 1 = day)
5 potential fire pixel
0 = no (if no, remaining QA fields except bit 23 are not set)
1 = yes
6 spare (set to 0)
7-10 background window size parameter, R
R = 0: unable to characterize background
R > 0: background characterized with (2R+1) by (2R+1) window
11 360 K T21 test (0 = fail, 1 = pass)
12 DT relative test i (0 = fail, 1 = pass)
13 DT absolute test ii (0 = fail, 1 = pass)
14 T21 relative test (0 = fail, 1 = pass)
15 T31 relative test (0 = fail, 1 = pass)
16 background fire T21 deviation test (0 = fail, 1 = pass)
17-19 spare (set to 0)
20 adjacent cloud pixel (valid only if fire mask = 7, 8, or 9)
0 = no
1 = yes
21 adjacent water pixel (valid only if fire mask = 7, 8, or 9)
0 = no
1 = yes
22-23 sun-glint level (0-3)
24 sun glint rejection flag (0 = false, 1 = true)
25 land-pixel desert boundary rejection flag (0 = false, 1 = true)
26 land-pixel coastal false alarm rejection flag (0 = false, 1 = true)
27 land-pixel forest clearing rejection test (0 = false, 1 = true)
28 water-pixel coastal false alarm rejection flag (0 = false, 1 = true)
29-31 spare (set to 0)
Note: For coast pixels, bits 24-28 will have a value of 0.
-----------------------------------------------------------------------------
The following Scientific Data Sets comprise the "Fire Pixel Table"; each is a
one-dimensional SDS having Dimension_3 elements and contains information
about each fire pixel. Each column of this table is (somewhat confusingly)
stored as a separate SDS to work around deficiencies in the HDF format.
Name Type Description
---- ---- -----------
FP_line int16 granule line of fire pixel
FP_sample int16 granule sample of fire pixel
FP_latitude float32 latitude of fire pixel (degrees)
FP_longitude float32 longitude of fire pixel (degrees)
FP_R2 float32 channel 2 reflectance of fire pixel
FP_T21 float32 channel 21/22 brightness temperature of fire
pixel (kelvins)
FP_T31 float32 channel 31 brightness temperature of fire
pixel (kelvins)
FP_MeanT21 float32 channel 21/22 brightness temperature of
background (kelvins)
FP_MeanT31 float32 channel 31 brightness temperature of
background (kelvins)
FP_MeanDT float32 mean background brightness temperature
difference (kelvins)
FP_MAD_T21 float32 channel 21/22 brightness temperature
mean absolute deviation of background
FP_MAD_T31 float32 channel 31 brightness temperature
mean absolute deviation of background
FP_MAD_DT float32 mean absolute deviation of background
brightness temperature difference (kelvins)
FP_power float32 fire radiative power (megawatts)
FP_AdjCloud uint8 number of adjacent cloud pixels (3 x 3 box)
FP_AdjWater uint8 number of adjacent water pixels (3 x 3 box)
FP_WinSize uint8 background window size
FP_NumValid int16 number of valid background pixels
FP_confidence uint8 detection confidence (%), range 0-100
FP_land uint8 1 = land fire pixel
0 = water fire pixel (i.e., glas flare)
FP_MeanR2 float32 background channel 2 reflectance
FP_MAD_R2 float32 channel 2 reflectance mean absolute
deviation of background
FP_ViewZenAng float32 view zenith angle (degrees)
FP_SolZenAng float32 solar zenith angle (degrees)
FP_RelAzAng float32 relative azimuth angle (degrees)
FP_CMG_row int16 CMG row (used for CMG production)
FP_CMG_col int16 CMG column (used for CMG production)
-----------------------------------------------------------------------------
Data stored within the CMG Scientific Data Sets are used in the production of
the fire CMG product.
Name Type Dimensions
---- ---- ----------
CMG_day uint16 Dimension_4, Dimension_6
CMG_night uint16 Dimension_5, Dimension_6