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
NCEI Metadata ID: gov.noaa.ngdc.mgg.geophysical_models:EMAG2
5 Generic Mapping Tools (GMT) Generic Mapping Tools (GMT)
    2008-05-15
1 GCMD Data Center Keywords Global Change Master Directory (GCMD) Data Center Keywords
    2020-01-09
1 GCMD Location Keywords Global Change Master Directory (GCMD) Location Keywords
    2020-01-09
1 GCMD Science Keywords Global Change Master Directory (GCMD) Science Keywords
    2020-01-09
1 International DOI Foundation (IDF)
    1 NOAA National Centers for Environmental Information
      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 https://epsg.org/crs_4326/WGS-84.html
      1 Maus, S. author
      3 originator http://geomag.org/info/Smaus/Doc/emag2.pdf
      3 http://geomag.org/info/Smaus/Doc/wdmam.pdf
      1 EPSG Registry European Petroleum Survey Group publisher https://epsg.org/home.html
      3 GCMD Landing Page NASA Goddard Space Flight Center, Earth Science Data and Information System custodian https://www.earthdata.nasa.gov/learn/find-data/idn/gcmd-keywords
      3 NCEI (pointOfContact) NOAA National Centers for Environmental Information ncei.info@noaa.gov pointOfContact https://www.ncei.noaa.gov/contact
      1 NOAA National Centers for Environmental Information publisher
      1 NCEI (distributor) NOAA National Centers for Environmental Information ncei.info@noaa.gov distributor https://www.ncei.noaa.gov/contact
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      CI_OnlineResource

      Count Component Linkage Name Description Function
      1 http://geomag.colorado.edu/emag2-earth-magnetic-anomaly-grid-2-arc-minute-resolution.html EMAG2 Home Page information
      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 https://epsg.org/crs_4326/WGS-84.html WGS 84 GML of World Geodetic System 1984 coordinate reference system. information
      1 https://epsg.org/home.html 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
      3 https://www.earthdata.nasa.gov/learn/find-data/idn/gcmd-keywords Global Change Master Directory (GCMD) Keywords The information provided on this page seeks to define how the GCMD Keywords are structured, used and accessed. It also provides information on how users can participate in the further development of the keywords. information
      3 https://www.ncei.noaa.gov/contact NCEI Contact Information Information for contacts at NCEI. information
      1 https://www.ncei.noaa.gov/metadata/geoportal/rest/metadata/item/gov.noaa.ngdc.mgg.geophysical_models:EMAG2/html Metadata Landing Page information
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      MD_Identifier or RS_Identifier

      Count Component Code
      1 NCEI Metadata ID: gov.noaa.ngdc.mgg.geophysical_models:EMAG2
      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 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 GeoTIFF Version 2 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. The color scale legend is at http://geomag.colorado.edu/images/EMAG2_scale.png
      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]
      2 JPG Version 2 Full Resolution Map of EMAG2 as a poster
      1 PDF Version 2 Full Resolution Map of EMAG2 as a poster
      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 NCEI copyright Produced by the NOAA National Centers for Environmental Information. 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.
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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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