==========================================================================
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 MOD17A2H to MOD17A2HGF.
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 MOD17A2 to MOD17A2H
!!! 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 MOD17A1HGF
MOD_PR17A2 archived 8-day composite GPP, and PSN at 500M PGE 37 MOD17A2HGF
MOD_PR17A3 archived Annual NPP at 500M PGE 38 MOD17A3HGF
-----------------------------------------------------------------------------
============================================================================
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 "MOD17A2HGF"
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/Terra 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/Terra 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/Terra 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
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