========================================================================== MODIS MOD17 L4 Tile 500M Gridded PRODUCT: PSN 8-day composite Revision 6.0.17 Mon Sep 16 2:01:00 EST 2019 Maosheng Zhao based on 6.0.2 MOD17A2.fs Revision 6.0.2 Fri June 14 5:01:00 EST 2013 Sudipta Sarkar Revision 5.2.3 Revised: Sat Apr 01 15:01:00 MST 2006 Petr Votava Revised: Thu Mar 23 11:10:00 MST 2006 Maosheng Zhao Revised: Thu Feb 17 15:20:00 MST 2006 Maosheng Zhao Revised: Thu Oct 06 15:26:00 MST 2005 Maosheng Zhao Revised: Mon Jun 20 17:26:00 MST 2005 Maosheng Zhao Revised: Fri Feb 16 00:01:00 PST 2005 _PV_ Revised: Wed Oct 30 17:15:47 MST 2002 JMG Lupine Logic, Inc. Revised: Wed Oct 23 11:14:00 PST 2002 Revised: Fri May 17 08:42:00 PST 2002 Revised: Fri Mar 10 12:13:19 MST 2000 Original: Tue Jul 14 16:53:59 MDT 1998 Product Identifier: MOD_PR17A2 gap-filled PSN 8-day composite Description: !!! NEW IN v6.0.17 implemented by LDOPE -- Output ESDT for gap-filled MOD17 changed from MYD17A2H to MYD17A2HGF. Gap-filled process is to first temporally fill unreliable FPAR/LAI from MOD15A2H using the reliable FPAR/LAI at the end of each year, and then calculate Gpp/PsnNet using these gap-filled FPAR/LAI as proposed by Zhao and his colleagues (Zhao et al., 2005). The GF MOD17 are meant to be equivalent of the same that was being produced from SCF. !!! NEW IN v6.0.2 implemented by LDOPE -- Input and output file resolutions changed from 1KM to 500M -- Output ESDT changed from MYD17A2 to MYD17A2H !!! NEW IN v.5.1.3 -- Correct MOD17A2 filename of LOCALGRANULEID in metadata caused by the bad side effect from the correction of NDAYS_COMPOSITED problem last time Modules influenced: ecsmeta.c psn_defs.h !!! NEW IN v.5.1.2 -- Correct NDAYS_COMPOSITED problem for abstract one extra day and control the maximum days of year, 365 or 366 Modules influenced: psn_pars.c psn_emd.c psn_defs.h !!! NEW IN v.5.1.0 -- modified annual NPP (MOD17A3) equation by altering algorithm for growth respiration (Rg). The previous Rg dependent on annual maximum LAI is unreasonable, because maximum LAI is strongly related to biomass, a state variable, but Rg is a flux variable, and it is part of remainder of GPP subtracted by maintenance respiration (Rm). Currently, Rg is assumed to account for 25% of NPP, in other words, NPP = 0.8*(GPP - Rm) -- modified constant q10_mr with value of 2.0 to q10_mr = 3.22 - 0.046*tavg the above equation is based on the review work by Tjoelker et al. in 2001 Citation: Tjoelker M. G., J. Oleksyn and P. Reich, 2001, Modelling respiration of vegetation: evidence for a general temperature-dependent Q10. Global Change Biology, 7: 223-230. -- update BPLUT again based on the recent MODIS GPP validation works from Bigfoot project and that in our lab. We increased light use efficiency for most forest biomes, and reduced that for most xeric biomes. We also made little changes to other parameters to keep up with all the above changes The changes will affect MOD17A1, A2 and A3. The change will improve the quality of MOD17. Modules influenced: psn_defs.h psn_calc.c !!! NEW IN v.5.0.2 -- incorporate GMAO (previous DAO) smoothing in the source code. Detailes are at Zhao M., F. A. Heinsch, R. R. Nemani, and S. W. Running, 2005, Improvements of the MODIS terrestrial gross and net primary production global data set. Remote Sensing of Environment, 95:164-176. The change will affect MOD17A1, A2 and A3, and will eliminate the big DAO footprint on MOD17 images. In the end, the change will improve the quality of MOD17 Modules influenced: psn_defs.h psn_prot.h psn_clim_adt.c psn_clim.c psn_clos.c psn_grid.c psn_xlate.c !!! NEW IN v.5.0.1 -- new QA bit layout to reflect the upstream changes in MOD15 0,0 MODLAND_QC bits '0' = Good Quality '1' = Other Quality 1,1 SENSOR '0' = Terra '1' = Aqua 2,2 DEADDETECTOR '0' = Detectors apparently fine for up to 50% of channels 1,2 '1' = Dead detectors caused >50% adjacent detector retrieval 3,4 CLOUDSTATE (this inherited from Aggregate_QC bits {0,1} cloud state) '00' = 0 Significant clouds NOT present (clear) '01' = 1 Significant clouds WERE present '10' = 2 Mixed cloud present on pixel '11' = 3 Cloud state not defined,assumed clear 5,7 SCF_QC (3-bit, (range '000'..100') 5 level Confidence Quality score. '000' = 0, Very best possible '001' = 1, Good,very usable, but not the best '010' = 2, Substandard due to geometry problems - use with caution '011' = 3, Substandard due to other than geometry problems - use with caution '100' = 4, Couldn't retrieve pixel (NOT PRODUCED AT ALL - non-terrestrial biome) '111' = 7, Fill Value !!! NEW IN V.4.2.0 --A new BPLUT is applied as of this version. --the range of the PsnNet_1km variable (digital representation) has been adjusted to{-30000 to 30,000} !!! NEW IN v4.1.0 !!! New in version 4.1.0: Added a new SDS that contains the PSN values as (GPP - maintenance respiration). The field is named PsnNet The MOD_PR17A2 (PGE 37) is the MODIS AM-1 Level-4 500M 8-day archived Photosyntheis data product. The PGE 36 daily algorithm updates the cumulative (intermediate) tiled product, adding the current data day's PSN measure to each pixel in the tile. At the conclusion of each 8-day period (indicated via a PGE 37 production rule), the PSN algorithm takes the PSN values accumulated over the 8-day period, and simply writes these (tiles) out as the official archived "8-day composite" GPP and PSN products, MODIS Parameter 3716. Note that the same temporal accumulation scheme is used to produce the annual Net Primary Productivity (NPP) product, where a total of (45) 8-day PSN products (stored in the intermediate gridfield Gpp_Rm_500M) are incrementally summed over the course of a given year, to eventually be output at the end of each year as the archived NPP annual product MODIS Parameter 2703). The definitions of the following MOD_PR17A2 specific (PSA) PRODUCT SPECIFIC ATTRIBUTES are defined in the ArchiveMetadata.0 block as ADDITIONALATRIBUTENAME{7..8}. These are represented using the ECS "INTEGER" data type, with percent values ranging {0..100} : PSA Name Definition --------------------------------------------------------------------- N_DAYS_COMPOSITED Number of days {1..8} contributing to final composite. This is fixed at (1) for MOD_PR17A1 (PGE 36), but should range from {1..8} for MOD_PR17 (PGE 37). QAPERCENTGOODPSN Tile-wise % of good or excellant quality PSN (or NPP) pixels. Versioning: We currently version-stamp our source code, ancillary files and product files with an identical version and release-timedate stamp, called UM_VERSION. Users may extract this version stamp from any product or ancillary file using a command like this: ncdump -h MOD17_ANC_RI15.hdf | grep UM_VERSION. The latest certified codeset carries this version stamp as a global file attribute in the product files, ancillary files, and within the executable: UM_VERSION = UM_VERSION = "UM_VERSION: U.MONTANA MODIS PGE36 Vers 5.5.0 Rev 15 Release 05.30.2013 09:58" Point of Contact: Petr Votava Principal Investigator(s): Steven W. Running NTSG Lab, School of Forestry University of Montana Missoula,MT 59812 WWW : https://www.ntsg.umt.edu/ =========================================================================== =========================================================================== A note to clarify MOD17 (PSN/NPP) 500M Level-4, Version 6.0.17 ALGORITHM, ESDT, and FILE designations: PROCESS IDs Status Description PGE ESDT ----------------------------------------------------------------------------- MOD_PR17A1 temporary 500M intermediate terms GPP-RM etc PGE 36 MYD17A1HGF MOD_PR17A2 archived 8-day composite GPP, and PSN at 500M PGE 37 MYD17A2HGF MOD_PR17A3 archived Annual NPP at 500M PGE 38 MYD17A3HGF ----------------------------------------------------------------------------- ============================================================================ Generic Constructs ECS Metadata Strings: Notes: 1. "FR" is an abbreviation for "FREE_RANGE". 2. "D/T" is an abbreviation for "DATE/TIME" 3. (A) means that multiple values are stored within a single array. 4. A value of "Variable" indicates that this value will vary according to the granule being processed. 5. "M" means class M. 6. (C) means that multiple values are stored as class members. CoreMetadata.0 This string will contain the following PVL fields: # Field Name Data of Value Type Values GROUP = INVENTORYMETADATA GROUP = CollectionDescriptionClass SHORTNAME STRING 1 "MYD17A2HGF" VERSIONID INTEGER 1 "6" END_GROUP = CollectionDescriptionClass GROUP = ECSDataGranule REPROCESSINGPLANNED STRING 1 "further update is anticipated" REPROCESSINGACTUAL STRING 1 Variable LOCALGRANULEID STRING 1 Variable DAYNIGHTFLAG STRING 1 Variable PRODUCTIONDATETIME D/T 1 Variable LOCALVERSIONID STRING 1 Variable END_GROUP = ECSDataGranule GROUP = PGEVersionClass PGEVERSION STRING 1 "6.0.17" 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 = SpatialDomainContainer GROUP = HorizontalSpatialDomainContainer GROUP = GPolygon 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 END_GROUP = GPolygon END_GROUP = HorizontalSpatialDomainContainer END_GROUP = SpatialDomainContainer GROUP = MeasuredParameter PARAMETERNAME STRING 1 "MOD_PR17A2" GROUP = QAFlags AUTOMATICQUALITYFLAG STRING 1 "Pass" AUTOMATICQUALITYFLAGEXPLANATION STRING 1 "No automatic quality assessment is performed in the PGE" SCIENCEQUALITYFLAG STRING 1 Variable SCIENCEQUALITYFLAGEXPLANATION STRING 1 "See http://landweb.nascom.nasa.gov/cgi-bin/QA_WWW/qaFlagPage.cgi?sat=terra for the product Science Quality status" END_GROUP = QAFlags GROUP = QAStats QAPERCENTINTERPOLATEDDATA INTEGER 1 Variable QAPERCENTMISSINGDATA INTEGER 1 Variable QAPERCENTOUTOFBOUNDSDATA INTEGER 1 Variable QAPERCENTCLOUDCOVER INTEGER 1 Variable END_GROUP = QAStats ENDGROUP = MeasuredParameter GROUP = AdditionalAttributes ADDITIONALATTRIBUTENAME STRING FR(C) Variable PARAMETERVALUE STRING FR(C) Variable ADDITIONALATTRIBUTENAME.1 = QAPERCENTGOODQUALITY ADDITIONALATTRIBUTENAME.2 = QAPERCENTOTHERQUALITY ADDITIONALATTRIBUTENAME.5 = HORIZONTALTILENUMBER ADDITIONALATTRIBUTENAME.6 = VERTICALTILENUMBER ADDITIONALATTRIBUTENAME.7 = TileID ******************************************************* * Other SCF defined PSA attributes: ******************************************************* ADDITIONALATTRIBUTENAME.8 = NDAYS_COMPOSITED ADDITIONALATTRIBUTENAME.9 = QAPERCENTGOODPSN ADDITIONALATTRIBUTENAME.10 = QAPERCENTGOODNPP END_GROUP = AdditionalAttributes GROUP = AssociatedPlatformInstrumentSensor ASSOCIATEDPLATFORMSHORTNAME STRING 1 "Terra/Aqua" ASSOCIATEDINSTRUMENTSHORTNAME STRING 1 "MODIS" ASSOCIATEDSENSORSHORTNAME STRING 1 "MODIS" END_GROUP = AssociatedPlatformInstrumentSensor ENDGROUP = INVENTORYMETADATA ProductMetadata.0 This string will contain the following PVL fields: # Field Name Data of Value Type Values GROUP = ARCHIVEDMETADATA GROUP = BoundingRectangle NORTHBOUNDINGCOORDINATE DOUBLE 1 Variable SOUTHBOUNDINGCOORDINATE DOUBLE 1 Variable EASTBOUNDINGCOORDINATE DOUBLE 1 Variable WESTBOUNDINGCOORDINATE DOUBLE 1 Variable END_GROUP = BoundingRectangle ALGORITHMPACKAGEACCEPTANCEDATE STRING 1 "2005-02-11" ALGORITHMPACKAGEMATURITYCODE STRING 1 "Normal" ALGORITHMPACKAGENAME STRING 1 "MOD17A2" ALGORITHMPACKAGEVERSION STRING 1 "6" INSTRUMENTNAME STRING 1 "MODIS" PROCESSINGDATETIME STRING 1 Variable GEOANYABNORMAL STRING 1 Variable GEOESTMAXRMSERROR DOUBLE 1 Variable LONGNAME "MODIS/Aqua Gross Primary Productivity Gap-Filled 8-Day Global 500M SIN Grid" STRING 1 PROCESSINGCENTER STRING 1 "MODAPS" PROCESSINGENVIRONMENT STRING 1 "set by uname" DESCRREVISION STRING 1 Variable LOCALINPUTGRANULEID STRING FR(A) Variable NUMBEROFGRANULES INTEGER 1 Variable GRANULEDAYNIGHTFLAG STRING FR(A) 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 NADIRDATARESOLUTION STRING 1 "500m" MAXIMUMOBSERVATIONS INTEGER 1 Variable SPSOPARAMETERS STRING 2 "3716" ENDGROUP = ARCHIVEDMETADATA StructuralMetadata.0 This string will be populated automatically by HDF-EOS. Grid Structure: MOD_Grid_MOD17A2 Data Fields: Gpp_500M, PsnNet_500M, Psn_QC_500M Dimensions: Dimension Dimension Name Value Dimension_0 YDim:MOD_Grid_MOD17A2H "DataRows" Dimension_1 XDim:MOD_Grid_MOD17A2H "DataColumns" Corner Locations: Corner Values UpperLeftPointMtrs (Variable, Variable) LowerRightPointMtrs (Variable, Variable) Geographic Grid Projection Parameters: Sinusoidal Projection Projection GCTP_SNSOID ProjParam[0] 6371007.181 ProjParam[1 to 7] 0.0 ProjParam[8] 0.0 ProjParam[9] 0.0 ProjParam[10] 0.0 ProjParam[11 to 12] 0.0 Spherecode -1 GridOrigin HDFE_CENTER Integrized Sinusoidal Projection Projection GCTP_ISINUS ProjParam[0] 6371007.181 ProjParam[1 to 7] 0.0 ProjParam[8] 21600 ProjParam[9] 0.0 ProjParam[10] 1.0 ProjParam[11 to 12] 0.0 Spherecode -1 GridOrigin HDFE_GD_UL =========================================================================== Data Field_1 ------------ Data Field Name: Gpp_500M Description: Gross Primary Production, 500M resolution Type: HDF-int16 Dimensions: Dimension Name Value YDim DataRows XDim DataColumns HDF Attributes: Number of Values or Max. Attribute Data String Value Type Length long_name STRING 59 "MODIS/Aqua Gross Primary Production (GPP) 8-Day L4 Global 500m SIN Grid" units STRING 8 "kg_C_m^2" valid_range INT16 2 0 30000 _FillValue INT16 1 32767 scale_factor FLOAT64 1 0.0001 add_offset FLOAT64 1 0.0 scale_factor_err FLOAT64 1 0.0 add_offset_err FLOAT64 1 0.0 calibrated_nt INT32 1 22 Data (HDF NCSA style) conversions (to and from digital to analytical): Gpp_500M = scale_factor * (Digital_form - add_offset) Digital_Form = (Gpp_500M / scale_factor) + add_offset =========================================== NEW NON-TERRESTRIAL FILL-VALUE ASSIGNMENTS =========================================== 32767 = _Fillvalue 32766 = land cover assigned as perennial salt or inland fresh Water 32765 = land cover assigned as barren,sparse veg (rock,tundra,desert) 32764 = land cover assigned as perennial snow,ice. 32763 = land cover assigned as "permanent" wetlands/inundated marshland 32762 = land cover assigned as urban/built-up 32761 = land cover assigned as "unclassified" or (not able to determine)? Data Field_2 ------------ Data Field Name: PsnNet_500M Description: Photosynthesis, as (gpp-rm), 500M resolution Type: HDF-int16 Dimensions: Dimension Name Value YDim DataRows XDim DataColumns HDF Attributes: Number of Values or Max. Attribute Data String Value Type Length long_name STRING 66 "MODIS/Aqua Net Photosynthesis (GPP - maint resp) 8-Day L4 Global 500m SIN Grid" units STRING 8 "kg_C_m^2" valid_range INT16 2 -30000 to 30000 _FillValue INT16 1 32767 scale_factor FLOAT64 1 0.0001 add_offset FLOAT64 1 0.0 scale_factor_err FLOAT64 1 0.0 add_offset_err FLOAT64 1 0.0 calibrated_nt INT32 1 22 Data (HDF NCSA style) conversions (to and from digital to analytical): PsnNet_500M = scale_factor * (Digital_form - add_offset) Digital_Form = (PsnNet_500M / scale_factor) + add_offset =========================================== NEW NON-TERRESTRIAL FILL-VALUE ASSIGNMENTS =========================================== 32767 = _Fillvalue 32766 = land cover assigned as perennial salt or inland fresh Water 32765 = land cover assigned as barren,sparse veg (rock,tundra,desert) 32764 = land cover assigned as perennial snow,ice. 32763 = land cover assigned as "permanent" wetlands/inundated marshland 32762 = land cover assigned as urban/built-up 32761 = land cover assigned as "unclassified" or (not able to determine)? Data Field_3 ------------ Data Field Name: Psn_QC_500m Description: QC (quality control) flags for Psn_500M biophysical variable, which is identical to FparLai_QC in MOD15A2HGF. BITS BITFIELD ------------- MODLAND_QC START 0 END 0 VALIDS 2 MODLAND_QC 0 = Good Quality (main algorithm with or without saturation) MODLAND_QC 1 = Other Quality (back-up algorithm or fill value) SENSOR START 1 END 1 VALIDS 2 SENSOR 0 = Terra SENSOR 1 = Aqua DEADDETECTOR START 2 END 2 VALIDS 2 DEADDETECTOR 0 = Detectors apparently fine for up to 50% of channels 1,2 DEADDETECTOR 1 = Dead detectors caused >50% adjacent detector retrieval CLOUDSTATE START 3 END 4 VALIDS 4 (this inherited from Aggregate_QC bits {0,1} cloud state) CLOUDSTATE 00 = 0 Significant clouds NOT present (clear) CLOUDSTATE 01 = 1 Significant clouds WERE present CLOUDSTATE 10 = 2 Mixed cloud present on pixel CLOUDSTATE 11 = 3 Cloud state not defined,assumed clear SCF_QC START 5 END 7 VALIDS 5 SCF_QC 000=0 Main (RT) algorithm used, best result possible (no saturation) SCF_QC 001=1 Main (RT) algorithm used, saturation occured. Good, very usable. SCF_QC 010=2 Main algorithm failed due to bad geometry, empirical algorithm used SCF_QC 011=3 Main algorithm faild due to problems other than geometry, empirical algorithm used SCF_QC 100=4 Pixel not produced at all, value coudn't be retrieved (possible reasons: bad L1B data, unusable MOD09GA data) Type: HDF-uint8 Dimensions: Dimension Name Value YDim DataRows XDim DataColumns HDF Attributes: Number of Values or Max. Attribute Data String Value Type Length long_name STRING 40 "MODIS/Terra QC for 8-day GPP/PSN" units STRING 14 "NoUnits" valid_range UINT8 2 0 254 _FillValue UINT8 1 255 ============================================================================