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Metadata Identifier: gov.noaa.ngdc.mgg.geophysical_models:EMAG2

Aggregation Info | Bands | Citations | Constraints | Coverage Descriptions | Dimensions | Extents | Formats | Geographic Bounding Box
Georectified Information | Georeferenceable Information | Identifiers | Instruments | Mediums | OnlineResources | Operations
Platforms | Process Steps | Range Elements | Reference Systems | Responsible Parties | Series | Sources | Spatial Grids | Temporal Extents

MD_DataIdentification

Count Component Title Abstract
1 EMAG2: Earth Magnetic Anomaly Grid (2-arc-minute resolution) EMAG2 is a global Earth Magnetic Anomaly Grid compiled from satellite, ship, and airborne magnetic measurements. It is a significant update of our previous candidate grid for the World Digital Magnetic Anomaly Map. The resolution has been improved from 3 arc-minutes to 2 arc-minutes, and the altitude has been reduced from 5 km to 4 km above the geoid. Additional grid and track line data have been included, both over land and the oceans. Wherever available, the original shipborne and airborne data were used instead of precompiled oceanic magnetic grids. Interpolation between sparse track lines in the oceans was improved by directional gridding and extrapolation, based on oceanic crustal age model. The longest wavelengths (>330 km) were replaced with the latests CHAMP satellite magnetic field model MF6.
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SV_Identification

none found
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CI_Citation

Count Component Title Date Citation Identifier
3 EMAG2 EMAG2: A 2-arc min resolution Earth Magnetic Anomaly Grid compiled from satellite, airborne, and marine magnetic measurements
    2009-08-07
1 EMAG2: Earth Magnetic Anomaly Grid (2-arc-minute resolution)
    2009-08-07
doi:10.7289/V5MW2F2P
5 Generic Mapping Tools (GMT) Generic Mapping Tools (GMT)
    2008-05-15
1 GCMD Data Center Keywords NASA/GCMD Data Center Keywords
    2015-03-01
    1995-04-24
1 GCMD Location Keywords NASA/GCMD Location Keywords
    2015-03-01
    1995-04-24
1 NASA/GCMD Keywords NASA/GCMD Science Keywords
    2015-03-01
    1995-04-24
3 WDMAM National Geophysical Data Center candidate for the World Digital Magnetic Anomaly Map
    2007-06-29
1 World Geodetic System 1984
    2007-08-27
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CI_Series

none found
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CI_ResponsibleParty

Count Component Individual Organization Position Email Role Linkage
1 resourceProvider http://www.epsg-registry.org/export.htm?gml=urn:ogc:def:crs:EPSG::4326
6 GCMD Valids http://gcmd.nasa.gov/learn/keyword_list.html
3 originator http://geomag.org/info/Smaus/Doc/emag2.pdf
1 Anna Milan Anna Milan DOC/NOAA/NESDIS/NCEI > National Centers for Environmental Information, NESDIS, NOAA, U.S. Department of Commerce Metadata Specialist Anna.Milan@noaa.gov pointOfContact
1 Brian Meyer Brian Meyer DOC/NOAA/NESDIS/NCEI > National Centers for Environmental Information, NESDIS, NOAA, U.S. Department of Commerce Brian.Meyer@noaa.gov pointOfContact
1 NCEI (publisher) DOC/NOAA/NESDIS/NCEI > National Centers for Environmental Information, NESDIS, NOAA, U.S. Department of Commerce publisher
2 Geomagnetic Modeling Team DOC/NOAA/NESDIS/NCEI > National Centers for Environmental Information, NESDIS, NOAA, U.S. Department of Commerce NCEI Geomagnetic Modeling Team geomag.models@noaa.gov pointOfContact http://www.ngdc.noaa.gov/geomag/
2 DOC/NOAA/NESDIS/NCEI > National Centers for Environmental Information, NESDIS, NOAA, U.S. Department of Commerce distributor http://geomag.colorado.edu/emag2-earth-magnetic-anomaly-grid-2-arc-minute-resolution.html
1 NGDC Geomagnetic Modeling Team (originator) DOC/NOAA/NESDIS/NGDC > National Geophysical Data Center, NESDIS, NOAA, U.S. Department of Commerce Geomagnetic Modeling Team geomag.models@noaa.gov originator http://www.ngdc.noaa.gov/geomag/
1 EPSG Registry European Petroleum Survey Group publisher http://www.epsg-registry.org/
3 GCMD User Support Office NASA GCMD User Support Office gcmduso@gcmd.gsfc.nasa.gov publisher http://gcmd.nasa.gov/MailComments/MailComments.jsf?rcpt=gcmduso
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CI_OnlineResource

Count Component Linkage Name Description Function
3 http://gcmd.nasa.gov/MailComments/MailComments.jsf?rcpt=gcmduso GCMD Feedback Form Have a Comment for the GCMD? information
3 http://gcmd.nasa.gov/learn/keyword_list.html GCMD's Science Keywords and Associated Directory Keywords This page describes the NASA GCMD Keywords, how to reference those keywords and provides download instructions. information
2 http://geomag.colorado.edu/emag2-earth-magnetic-anomaly-grid-2-arc-minute-resolution.html
1 http://geomag.colorado.edu/images/EMAG2/EMAG2.kmz Google Earth Plugin for Google Earth. Requires installation of Google Earth. download
1 http://geomag.colorado.edu/images/EMAG2/EMAG2_V2.grd GMT Grid A GMT (Generic Mapping Tools) compatible netCDF grid with resolution of 2-arc-minutes. The values (nT) are stored as 32-bit floating point. download
1 http://geomag.colorado.edu/images/EMAG2/EMAG2_V2.tif GIS TIFF A georeferenced TIFF (GeoTIFF) with a resolution of 2-arc-minutes, which can be opened by ESRI ArcGIS or any other GIS application. The values (nT) are stored as 32-bit floating point. download
1 http://geomag.colorado.edu/images/EMAG2/EMAG2_V2.xyz.gz XYZ/Zip EMAG2 ASCII grid of the magnetic total intensity at 4km above WGS84 ellipsoid. download
1 http://geomag.colorado.edu/images/EMAG2/EMAG2_image_V2.jpg EMAG2 Full Resolution Map image JPG of Full Resolution Map of EMAG2 as an image. download
1 http://geomag.colorado.edu/images/EMAG2/EMAG2_image_V2.tif Color-relief A 24-bit RGB georeferenced TIFF (GeoTIFF) color-relief visualization of the EMAG2 grid, which can be opened by ArcGIS or any other GIS application. download
1 http://geomag.colorado.edu/images/EMAG2/EMAG2_no_directional_gridding_2009-01-06.xyz.gz XYZ/zip EMAG2 (Version 2.0) ASCII grid of the magnetic total intensity at 4km above WGS84 ellipsoid. This version was produced without directional gridding. Therefore, it has much sparser coverage but reflects more closely the actual measurements. download
1 http://geomag.colorado.edu/images/EMAG2/EMAG2_poster_V2.jpg EMAG2 Full Resolution Map poster JPG of Full Resolution Map of EMAG2 as a poster. download
1 http://geomag.colorado.edu/images/EMAG2/EMAG2_poster_V2.pdf EMAG2 Full Resolution Map poster PDF of Full Resolution Map of EMAG2 as a poster download
1 http://geomag.colorado.edu/images/EMAG2/emag2.pdf EMAG2: A 2-arc-minute resolution Earth Magnetic Anomaly Grid compiled from satellite, airborne and marine magnetic measurements Preprint of manuscript "EMAG2: A 2-arc-minute resolution Earth Magnetic Anomaly Grid compiled from satellite, airborne and marine magnetic measurements", submitted for publication to Geochem. Geophys. Geosyst. download
3 http://geomag.org/info/Smaus/Doc/emag2.pdf
3 http://geomag.org/info/Smaus/Doc/wdmam.pdf
1 http://www.epsg-registry.org/ European Petroleum Survey Group Geodetic Parameter Registry Registry that accesses the EPSG Geodetic Parameter Dataset, which is a structured dataset of Coordinate Reference Systems and Coordinate Transformations. search
1 http://www.epsg-registry.org/export.htm?gml=urn:ogc:def:crs:EPSG::4326 WGS 84 GML of World Geodetic System 1984 coordinate reference system. information
3 http://www.ngdc.noaa.gov/geomag/
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MD_Identifier or RS_Identifier

Count Component Code
5 Processing steps were carried out collectively by the developers of the model. These developers are listed as authors of the associated paper "EMAG2: A 2-arc minute resolution Earth Magnetic Anomaly Grid compiled from satellite, airborne, and marine magnetic measurements" found at http://geomag.colorado.edu/images/EMAG2/emag2.pdf
1 doi:10.7289/V5MW2F2P
1 urn:ogc:def:crs:EPSG::4326
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EX_Extent

Bounding Box Temporal Extent
Count Component Description West East North South Start End
1 -180 180 90 -90 1946-01-01 2008-12-01
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EX_GeographicBoundingBox

Count Component West East North South
1 -180 180 90 -90
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EX_TemporalExtent

Count Component Start End
1 1946-01-01 2008-12-01
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MD_Format

Count Component Name Version specification
1 Article Version 2 Preprint of manuscript "EMAG2: A 2-arc-minute resolution Earth Magnetic Anomaly Grid compiled from satellite, airborne and marine magnetic measurements", submitted for publication to Geochem. Geophys. Geosyst.
1 Color-relief Version 2 A 24-bit RGB georeferenced TIFF (GeoTIFF) color-relief visualization of the EMAG2 grid, which can be opened by ArcGIS or any other GIS application. The color scale legend is at http://geomag.colorado.edu/images/EMAG2_scale.png
3 Full Resolution Map Version 2 PDF of EMAG2 as a poster
1 GIS TIFF Version 2 A georeferenced TIFF (GeoTIFF) with a resolution of 2 arc-minutes, which can be opened by ESRI ArcGIS or any other GIS application. The values (nT) are stored as 32-bit floating point.
1 GMT Grid Version 2 A GMT (Generic Mapping Tools) compatible net CDF grid with resolution of 2-arc-minutes. The values (nT) are stored as 32-bit floating point.
1 Google Earth Version 2 Plugin for Google Earth. Requires installation of Google Earth. See also https://productforums.google.com/forum/?fromgroups#!msg/gec-dynamic-data-layers/yYsaTFnIzYQ/RVwprs5WhPQJ[1-25]
1 XYZ/Zip Version 2 ASCII grid of the magnetic total intensity at 4km above WGS84 ellipsoid.
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MD_Medium

none found
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MD_Constraints

Count Component Use Limitation
1 Cite as: Stefan Maus (2009): EMAG2: Earth Magnetic Anomaly Grid (2-arc-minute resolution). National Geophysical Data Center, NOAA. Model. doi:10.7289/V5MW2F2P [access date]
1 NGDC copyright Produced by the NOAA National Geophysical Data Center. Not subject to copyright protection within the United States.
1 Navigation Not to be used for navigation. Although these data are of high quality and useful for planning and modeling purposes, they are not suitable for navigation. For navigation, please refer to the NOS nautical chart series.
1 NOAA Liability While every effort has been made to ensure that these data are accurate and reliable within the limits of the current state of the art, NOAA cannot assume liability for any damages caused by any errors or omissions in the data, nor as a result of the failure of the data to function on a particular system. NOAA makes no warranty, expressed or implied, nor does the fact of distribution constitute such a warranty.
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MD_ReferenceSystem

Count Component Code Authority Title
1 WGS84 urn:ogc:def:crs:EPSG::4326 World Geodetic System 1984
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MD_GridSpatialRepresentation

Count Component Number of Dimensions Cell Geometry Code
1 2 area
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MD_Georeferenceable or MI_Georeferenceable

none found
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MD_Georectified or MI_Georectified

none found
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MD_Dimension

Count Component Name Code Size
1 row 10801
1 column 5401
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MD_CoverageDescription or MI_CoverageDescription

Count Component Attribute Description Content Type
1 Grid Cell
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MD_Band or MI_Band

Count Component Identifier Descriptor
1 Magnetic Anomaly
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MI_RangeElementDescription

Count Component Name Definition
1 Empty Grid Cell Representation of grid cell with no measurement value.
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MD_AggregateInformation

none found
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LE_Source or LI_Source

none found
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LE_ProcessStep or LI_ProcessStep

Count Component DateTime Description
1 Merged grids at 4 km altitude above geoid using Least Squares Collocation.
1 From all original ship and airborne measurements: subtracted main and external fields given by the Comprehensive Model (Sabaka et al., 2004)
1 Line-leveled the trackline data, minimizing misfits from neighboring and cross-over tracks.
1 Merged the trackline data with the grid at 4 km altitude using Least Squares Collocation with anisotropic correlation function (directional gridding).
1 Substituted spherical harmonic degrees less than or equal to 120 (33 km wavelength) with CHAMP satellite magnetic anomaly model MF6 (Maus et al., 2008).
1 2015-04-22T00:00:00 NOAA created the National Centers for Environmental Information (NCEI) by merging NOAA's National Climatic Data Center (NCDC), National Geophysical Data Center (NGDC), and National Oceanographic Data Center (NODC), including the National Coastal Data Development Center (NCDDC), per the Consolidated and Further Continuing Appropriations Act, 2015, Public Law 113-235. NCEI launched publicly on April 22, 2015.
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MI_Operation

none found
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MI_Platform

none found
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MI_Instrument

none found
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