MODIS L2 Fire Version 5 File Specification Revision 5.0.1, 20 February 2007 This document specifies the format for the Terra MODIS Level 2 Active Fire product (MOD14). Point of Contact: Louis Giglio Science Systems and Applications Inc. NASA Goddard Space Flight Center, Code 614.4 Greenbelt, MD 20771 (301) 614-6698 louis_giglio@ssaihq.com giglio@hades.gsfc.nasa.gov Principal Investigator: Chris Justice University of Maryland justice@hermes.geog.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 Number of fire pixels detected in granule. MissingPix int32 Number ofpixels classified as "missing" in granule. LandPix int32 Number of land pixels in granule. WaterPix int32 Number of water pixels in granule. WaterAdjacentFirePix int32 Number of fire pixels adjacent to one or more water pixels within granule. CloudAdjacentFirePix int32 Number of fire pixels adjacent to one or more cloud pixels within granule. UnknownPix int32 Number of 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 sun-glint contaminated land pixels in granule. GlintRejectedFirePix int32 Number of apparent fire pixels rejected as being caused by sun-glint. DayPix int32 Number of daytime pixels in granule. NightPix int32 Number of nighttime pixels in granule. ProcessVersionNumber string Internal version number (e.g. "3.1.0"). 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 water 4 cloud 5 no fire 6 unknown 7 fire (low confidence) 8 fire (nominal confidence) 9 fire (high confidence) ----------------------------------------------------------------------------- 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 MODLAND QA bits 00 = fire/no-fire determined at optimum confidence 01 = fire/no-fire determined at less than optimum confidence 10 = no determination made due to cloud cover 11 = no determination made due to other reason(s) 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) 17-20 spare (set to 0) 21 adjacent cloud pixel (valid only if fire mask = 7, 8, or 9) 0 = no 1 = yes 22 adjacent water pixel (valid only if fire mask = 7, 8, or 9) 0 = no 1 = yes 23 sun-glint level (0-3) 24 sun glint rejection flag (0 = false, 1 = true) 25 hot-surface boundary rejection flag (0 = false, 1 = true) 26 coastal false alarm rejection flag (0 = false, 1 = true) 27-31 spare (set to 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 ----------------------------------------------------------------------------- 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 SDS Attributes: Attribute Type Quantity Value --------- ---- -------- ----- long_name string 1 Climate Modeling Grid information