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    • U.S. Geoid Heights, Scientific Model (G96SSS)

    Metadata Updated: October 18, 2024

    This 2' geoid height grid for the conterminous United States is the G96SSS model. The computation used about 1.8 million terrestrial and marine gravity data held in the National Geodetic Survey gravity data base in July 1996. These data were augmented by gravity data contributions from NGA (former National Imagery and Mapping Agency (former Defence Mapping Agency)). By means of a Fast Fourier Transform (FFT) technique, high frequency corrections were made to an underlying EGM96 geopotential model through a remove, compute, and restore process. The gravity values are based on the International Gravity Standardization Net 1971 (IGSN71). The geoid heights are referred to the Geodetic Reference System 1980 (GRS80) ellipsoid. Unlike GEOID96, the G96SSS grid does not incorporate GPS on leveled benchmarks. The G96SSS model is a gravimetric geoid in a geocentric, ITRF94(1996.0) reference frame. It is necessary to subtract 12.0 cm from the G96SSS values to obtain the geoid undulation between the best-fit global geopotential surface and the GRS80 ellipsoid (both expressed in a tide free system). 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.

    Access & Use Information

    License: No license information was provided. If this work was prepared by an officer or employee of the United States government as part of that person's official duties it is considered a U.S. Government Work.

    Downloads & Resources

    Dates

    Metadata Date September 25, 2017
    Metadata Created Date October 18, 2024
    Metadata Updated Date October 18, 2024
    Reference Date(s) January 1, 1999 (publication)
    Frequency Of Update irregular

    Metadata Source

    Harvested from NGDC MGG Geophysics

    Other Data Resources

    Additional Metadata

    Resource Type Dataset
    Metadata Date September 25, 2017
    Metadata Created Date October 18, 2024
    Metadata Updated Date October 18, 2024
    Reference Date(s) January 1, 1999 (publication)
    Responsible Party NOAA National Centers for Environmental Information (Point of Contact)
    Contact Email
    Guid gov.noaa.ngdc.mgg.geophysics:G01446
    Access Constraints Distribution liability: NOAA and NCEI make no warranty, expressed or implied, regarding these data, nor does the fact of distribution constitute such a warranty. NOAA and NCEI cannot assume liability for any damages caused by any errors or omissions in these data. If appropriate, NCEI can only certify that the data it distributes are an authentic copy of the records that were accepted for inclusion in the NCEI archives., Use Constraints: If you use this data, please cite the National Geophysical Data Center and the originator of the data., Access Constraints: None
    Bbox East Long -66
    Bbox North Lat 53
    Bbox South Lat 24
    Bbox West Long -130
    Coupled Resource
    Frequency Of Update irregular
    Harvest Object Id 2edceff4-f8f8-4d5b-8bd6-1eadfb8ae061
    Harvest Source Id 80dfcf5d-5e08-457e-83e4-cfc696e378bc
    Harvest Source Title NGDC MGG Geophysics
    Licence
    Lineage
    Metadata Language eng; USA
    Metadata Type geospatial
    Old Spatial {"type": "Polygon", "coordinates": [[[-130.0, 24.0], [-66.0, 24.0], [-66.0, 53.0], [-130.0, 53.0], [-130.0, 24.0]]]}
    Progress completed
    Spatial Data Service Type
    Spatial Reference System urn:ogc:def:crs:EPSG::5715
    Spatial Harvester True

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