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Mexico East-West Deflections (DMEX97)

This 2' surface deflection of the vertical grid for Mexico, and North-Central is the DMEX97 model. The computation used about one million terrestrial and marine gravity measurements held in the NGS database as of March 1997. These gravity measurements were augmented by data contributions from NGA (former National Imagery and Mapping Agency), and satellitealtimeter derived gravity anomalies computed by Sandwell and Smith (1997). The deflection values themselves were obtained by numericaldifferentiation of cubic spline models along the parallels of the MEXICO97 geoid grid, followed by a correction for curvature of the plumb line, yielding surface deflections of the vertical. Since the EGM96 model was used to fill data gaps south of 20 degrees North latitude, the deflections in and around those regions will be less accurate. The gravity values are based on the International Gravity Standardization Net 1971 (IGSN71). The deflections are referred to Geodetic Reference System 1980 (GRS80) ellipsoidalnormals oriented in the International Terrestrial Reference Frame 1994 (ITRF94(1996.0)). Additional information is available at:http://www.ngs.noaa.gov/We are particularly grateful to NGA (former National Imagery and Mapping Agency) for their assistance and their data contributions.

Use Constraints: If you use this data, please cite the National Geophysical Data Center and the originator of the data.

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    Distribution Formats
    • Binary
    Distributor DOC/NOAA/NESDIS/NGDC - National Geophysical Data Center
    Point of Contact Susan McLean
    DOC/NOAA/NESDIS/NGDC > National Geophysical Data Center, NESDIS, NOAA, U.S. Department of Commerce
    (303) 497-6478
    Susan.McLean@noaa.gov
    Documentation links not available.
    Originator
    • DOC/NOAA/NESDIS/NGDC - National Geophysical Data Center
    Publisher
    • DOC/NOAA/NESDIS/NGDC - National Geophysical Data Center
    Date(s)
    • publication: 1999-01-01
    Edition: 1999 Edition
    Dataset Progress Status Complete
    Data Update Frequency: Irregular
    Purpose: To provide easy access to global and regional gravity data and related models for scientific studies.
    Time Period:  to 
    Spatial Reference System: urn:ogc:def:crs:EPSG::5715
    Spatial Bounding Box Coordinates:
    N: 33
    S: 14
    E: -75
    W: -119
    Spatial Coverage Map:
    Themes
    • EARTH SCIENCE>SOLID EARTH>Geodetics/Gravity>Control Surveys
    • EARTH SCIENCE>SOLID EARTH>Geodetics/Gravity>Gravitational Field
    • EARTH SCIENCE>SOLID EARTH>Geodetics/Gravity>Gravity
    • EARTH SCIENCE>SOLID EARTH>Geodetics/Gravity>Reference Systems
    • EARTH SCIENCE>SOLID EARTH>Geodetics/Gravity>Satellite Orbits
    • Absolute Gravity
    • Bouguer Gravity
    • Free Air Anomaly
    • Gridded Gravity
    • Land Gravity
    • Observed Gravity
    • WDC/SEG, BOULDER>World Data Center for Solid Earth Geophysics, Boulder
    • DOC/NOAA/NESDIS/NGDC > National Geophysical Data Center, NESDIS, NOAA, U.S. Department of Commerce
    Places
    • Continent>North America>Mexico
    Use Constraints
    • Use Constraints: If you use this data, please cite the National Geophysical Data Center and the originator of the data.
    Access Constraints
    • Access Constraints: None
    Fees
    • Depends on the data set
    Source Datasets
    • Mexico East-West Deflections (DMEX97)
      • Description of Source: Source Contribution: Gravity survey data Source Type: varies
      • Temporal extent used:   to 
    Lineage Statement Lineage statement not available.
    Processor
    • DOC/NOAA/NESDIS/NGDC > National Geophysical Data Center, NESDIS, NOAA, U.S. Department of Commerce
    Processing Steps
    • All data were processed by the source before being forwarded to the National Geophysical Data Center

    Metadata Last Modified: 2012-10-26

    For questions about the information on this page, please email: Brian.Meyer@noaa.gov