VNP29 Product File Specification

Version:	V1.0.0
Revision:	0
Date:		17 January 2019
ESDT:		VNP29
Product name:	Sea Ice
Product Level:	2
PGE:		508

Point of Contact:	George Riggs
			SSAI
			NASA, GSFC, Code 971
			Greenbelt, MD 20771
			301-614-5650
			George.A.Riggs.1@gsfc.nasa.gov

Principal Investigator: Dorothy K. Hall
			NASA, GSFC, Code 971
			Greenbelt, MD 20771
			301-614-5771
			Dorothy.K.Hall@nasa.gov

Co-Investigator: 	George Riggs
			SSAI
			NASA, GSFC, Code 971
			Greenbelt, MD 20771
			301-614-5650
			George.A.Riggs.1@gsfc.nasa.gov
			
			Mark Tschudi
			University of Colorado
			ECNT 320, 431 UCB, Boulder, Colorado 80309
			303-492-8274
			mark.tschudi@colorado.edu

Description:
The VIIRS sea ice extent algorithm and output data have been designed to be compatible with Version 6 MODIS sea ice extent 
from Aqua and Terra, to ensure continuity between the collections and facilitate climate-data records (CDRs) from the three 
sensors. Differences in the algorithms reflect physical differences between the instruments, for example spatial resolution 
and the location of spectral bands.

Unlike MODIS, VIIRS sea ice cover and ice surface temperature (IST) are being produced as separate products: VNP29 
(this data set) and VNP30 (IST). This decision allows the data to be produced at the spatial resolution of the underlying 
acquisition bands, or 375 m for sea ice cover (I-band) and 750 m for IST (M-band).

SDSs produced:
     SeaIceCover_Map
     SeaIceCOver_Basic_QA
     Algorithm_QA_Flags
     latitude
     longitude

The data product and algorithm are described in the VIIRS Sea Ice Data Product User Guide. The user should refer to that 
document for detailed description of the product, how to interpret the product and attributes (metadata).  Other information 
may be found at https://nsidc.org/data/VNP29

Contents:
Global Metadata:

Name:			Type:	Num_Val:	Source:	Value:

AlgorithmType		STRING	1		STIG	"OPS"
AlgorithmVersion	STRING	1		STIG	Variable
CloudCover		STRING	1		STIG	Variable
Conventions		STRING	1		STIG	Variable
DayNightFlag		STRING	1		STIG	"Day"
EastBoundingCoord	FLOAT	1		STIG	Variable
WestBoundingCoord 	FLOAT	1		STIG	Variable
NorthBoundingCoord 	FLOAT	1		STIG	Variable
SouthBoundingCoord	FLOAT	1		STIG	Variable
GRingPointLongitude	DOUBLE	4		PGE	Variable
GRingPointLatitude	DOUBLE	4		PGE	Variable
RangeEndingDate		STRING	1		PGE	Variable
RangeEndingTime		STRING	1		PGE	Variable
RangeBeginningDate	STRING	1		PGE	Variable
RangeBeginningTime	STRING	1		PGE	Variable
StartTime		STRING	1		PGE	Variable
EndTime			STRING	1		PGE	Variable	
IceCover		STRING	1		STIG	Variable
InputPointer		STRING	3		PGE	Variable
InstrumentShortname	STRING	1		PGE	"VIIRS"
LocalGranuleID		STRING	1		PGE	Variable
LongName		STRING	1		STIG	"VIIRS/NPP Sea Ice Cover 6-Min L2 Swath 375m"
PGEVersion		STRING	1		PGE	Variable
PGE_EndTime		STRING	1		PGE	Variable
PGE_Name		STRING	1		PGE	"PGE508"
PGE_StartTime		STRING	1		PGE	Variable
Percent_ocean_in_swath	STRING	1		STIG	Variable
Platform_Short_Name	STRING	1		STIG	"NPP"
ProcessVersion		STRING	1		STIG	Variable
ProcessingEnvironment	STRING	1		PGE	Variable
ProductionTime		DATETIME1		TK	Variable
ProxyDataType		STRING	1		STIG	"Operational Data"
Resolution		STRING	1		STIG	"Imagery"
SatelliteInstrument	STRING	1		PGE	"NPP_OPS"
ShortName		STRING	1		MCF	"VNP29"
cdm_data_type		STRING	1		PGE	"swath"
creator_email		STRING	1		PGE	"modis-ops@lists.nasa.gov"
creator_url		STRING	1		PGE	"http://ladsweb.nascom.nasa.gov"
identifier_product_doi	STRING	1		PGE	"10.5067/VIIRS/VNP29.001"
identifier_product_doi_authority
			STRING	1		PGE	"http://dx.doi.org"
institution		STRING	1		PGE	"NASA Goddard Space Flight Center"
keywords_vocabulary	STRING	1		PGE	"NASA Global Change Master Directory (GCMD) Science Keywords"
license			STRING	1		PGE	"http://science.nasa.gov/earth-science/earth-science-data/data-information-policy/"
naming_authority	STRING	1		PGE	"gov.nasa.gsfc.VIIRSland"
processing_level	STRING	1		PGE	"2"
project			STRING	1		PGE	"VIIRS Land SIPS Sea Ice Cover Project"
publisher_email		STRING	1		PGE	"modis-ops@lists.nasa.gov"
publisher_name		STRING	1		PGE	"LAADS"
publisher_url		STRING	1		PGE	"http://ladsweb.nascom.nasa.gov"
stdname_vocabulary	STRING	1		PGE	"NetCDF Climate and Forecast (CF) Metadata Convention"
title			STRING	1		STIG	"VIIRS Sea Ice Cover"

===============================================================================

SDS Name:	latitude
Description:	Latitude data
Number Type:	DFNT_FLOAT32
Rank:		2
Dimension sizes:(6464,6400)
Dimension Names:
	Dimension0:	"number_of_lines"
	Dimension1:	"number_of_pixels"

SDS Attributes: 
Name:			Type:		Num_val:	Source:	Value:
long_name		STRING		1		PGE	"Latitude data"
units			STRING		1		PGE	"degrees_north"
valid_range		DFNT_FLOAT32	2		PGE	-90.00000, 90.0000
_FillValue		DFNT_FLOAT32	1		PGE	-999.0000

===============================================================================

SDS Name:	longitude
Description:	Longitude data
Number Type:	DFNT_FLOAT32
Rank:		2
Dimension sizes:(6464,6400)
Dimension Names:
	Dimension0:	"number_of_lines"
	Dimension1:	"number_of_pixels"

SDS Attributes: 
Name:			Type:		Num_val:	Source:	Value:
long_name		STRING		1		PGE	"Longitude data"
units			STRING		1		PGE	"degrees_east"
valid_range		DFNT_FLOAT32	2		PGE	-180.00000, 180.0000
_FillValue		DFNT_FLOAT32	1		PGE	-999.0000

===============================================================================

SDS Name:	SeaIceCover_Map

Description:	Sea Ice Cover map with masks
Number Type:	DFNT_UINT8
Rank:		2
Dimension sizes:(6464,6400)
Dimension Names:
	Dimension0:	"number_of_lines"
	Dimension1:	"number_of_pixels"

SDS Attributes:
Name:			Type:		Num_val:	Source:	Value:
long_name		STRING		string length	PGE	"Sea Ice Cover map with masks"
valid_range		DFNT_UINT8	2		PGE	0,100
_FillValue		DFNT_UNIT8	1		PGE	255
coordinates		STRING		1		PGE	"latitude longitude"
mask_meanings		STRING		1		PGE	"200-missing, 201-no_decision, 211-night, 225-land, 237-inland_water, 250-cloud, 252-unusable_L1B_data, 253-bowtie_trim, 254-no_L1B_data"
mask_values		DFNT_UINT8	9		PGE	200, 201, 211, 225, 237, 250, 252, 253, 254

===============================================================================

SDS Name:	Algorithm_QA_Flags

Description:	Algorithm QA Flags for Ice Cover
Number Type:	DFNT_UINT8
Rank:		2
Dimension sizes:(6464,6400)
Dimension Names:
	Dimension0:	"number_of_lines"
	Dimension1:	"number_of_pixels"

SDS Attributes:
Name:			Type:		Num_val:	Source:	Value:
long_name		STRING		string length	PGE	"Algorithm QA Flags for Ice Cover"
_FillValue		DFNT_UNIT8	1		PGE	0
coordinates		STRING		1		PGE	"latitude longitude"
flag_masks		STRING		1		PGE	"1b, 2b, 4b, 8b, 16b, 32b, 64b, 128b"
flag_meanings		STRING		1		PGE	"spare low_visible_screen low_NDSI_screen spare spare high_SWIR_screen/flag spare solar_zenith_flag"

===============================================================================

SDS Name:	SeaIceCover_Basic_QA

Description:	Basic QA Ice Cover
Number Type:	DFNT_UINT8
Rank:		2
Dimension sizes:(6464,6400)
Dimension Names:
	Dimension0:	"number_of_lines"
	Dimension1:	"number_of_pixels"

SDS Attributes:
Name:			Type:		Num_val:	Source:	Value:
long_name		STRING		string length	PGE	"Basic QA Ice Cover"
_FillValue		DFNT_UNIT8	1		PGE	255
coordinates		STRING		1		PGE	"latitude longitude"
QA_value_meanings	STRING		1		PGE	"0-best, 1-good, 2-poor, 3-bad, 4-other"
mask_meanings		STRING		1		PGE	"211-night, 225-land, 237-inland_water, 250-cloud, 252-unusable_L1B_data, 253-bowtie_trim, 254-no_L1B_data"
mask_values		DFNT_UINT8	7		PGE	211, 225, 237, 250, 252, 253, 254
valid_range		DFNT_UINT8	2		PGE	0,4

===============================================================================