Geoid Height and Deflections of the Vertical Models
In Gauss' words, the geoid is "the mathematical figure of the Earth". This figure is an equipotential surface coincident with the idealized mean sea surface. The geoid can be computed from the geodetic boundary value problems that use gravity data as its boundary value. A geoid model computed using gravity data is called a gravimetric geoid. On the other hand, geoid height at bench marks can also be computed using data from spirit leveling and the Global Positioning System (GPS). A geoid model that is fixed to the GPS/leveling data is called a hybrid geoid. Both geoid models can serve as the zero-height-surface of a country's height system by selection. To satisfy this need, National Geodetic Survey has published a series of geoid models (https://geodesy.noaa.gov/GEOID).
The vast majority of navigation and positioning applications utilize a hybrid geoid model with the latest model being GEOID18 for CONUS and Puerto Rico/U.S. Virgin Islands and GEOID12B for all other states and territories of the United States. The corresponding gravimetric geoid for these regions is xGEOID19B and USGG2012, respectively. All models are provided at 1 arc-minute resolution.
Complete Metadata
| @type | dcat:Dataset |
|---|---|
| accessLevel | non-public |
| contactPoint |
{
"fn": "Not provided - Contact data.gov",
"hasEmail": "mailto:datagovsupport@gsa.gov"
}
|
| describedByType | application/octet-steam |
| description | In Gauss' words, the geoid is "the mathematical figure of the Earth". This figure is an equipotential surface coincident with the idealized mean sea surface. The geoid can be computed from the geodetic boundary value problems that use gravity data as its boundary value. A geoid model computed using gravity data is called a gravimetric geoid. On the other hand, geoid height at bench marks can also be computed using data from spirit leveling and the Global Positioning System (GPS). A geoid model that is fixed to the GPS/leveling data is called a hybrid geoid. Both geoid models can serve as the zero-height-surface of a country's height system by selection. To satisfy this need, National Geodetic Survey has published a series of geoid models (https://geodesy.noaa.gov/GEOID). The vast majority of navigation and positioning applications utilize a hybrid geoid model with the latest model being GEOID18 for CONUS and Puerto Rico/U.S. Virgin Islands and GEOID12B for all other states and territories of the United States. The corresponding gravimetric geoid for these regions is xGEOID19B and USGG2012, respectively. All models are provided at 1 arc-minute resolution. |
| distribution |
[
{
"@type": "dcat:Distribution",
"title": "NGS GEOID Homepage",
"mediaType": "placeholder/value",
"description": "Geoid model landing page can be used to access various models, datasets, software, applications, and additional documentation.",
"downloadURL": "https://geodesy.noaa.gov/GEOID/",
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},
{
"@type": "dcat:Distribution",
"title": "API for NGS GEOID",
"mediaType": "placeholder/value",
"description": "Landing page for GEOID API that allows interpolation of various geoid models at user provided geographic locations.",
"downloadURL": "https://geodesy.noaa.gov/web_services/geoid.shtml",
"describedByType": "application/octet-steam"
},
{
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"title": "GCMD Keyword Forum Page",
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"description": "Global Change Master Directory (GCMD). 2025. GCMD Keywords, Version 22. Greenbelt, MD: Earth Science Data and Information System, Earth Science Projects Division, Goddard Space Flight Center (GSFC), National Aeronautics and Space Administration (NASA). URL (GCMD Keyword Forum Page): https://forum.earthdata.nasa.gov/app.php/tag/GCMD+Keywords",
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|
| identifier | gov.noaa.nmfs.inport:39739 |
| issued | 1996-01-01T00:00:00.000+00:00 |
| keyword |
[
"Geodetic Control Theme",
"NGDA",
"National Geospatial Data Asset",
"NGDAID50",
"DEFLEC12A",
"DEFLEC12B",
"DEFLEC18",
"EGM2008",
"Elevation",
"GEOID03",
"GEOID12A",
"GEOID12B",
"GEOID18",
"Geodesy",
"Geodetic/Global Positioning",
"Gravity Fields",
"INTERIOR AND CRUST",
"LAND",
"Terrain Elevation",
"Topographic Data",
"USGG2012",
"Alaska",
"American Samoa",
"Caribbean",
"Commonwealth of the Northern Mariana Islands",
"Guam",
"Hawaii",
"Mexico",
"Puerto Rico",
"United States",
"Virgin Islands",
"DOC/NOAA/NOS/NGS > National Geodetic Survey, National Ocean Service, NOAA, U.S. Department of Commerce",
"NGS Metadata Library"
]
|
| landingPage | https://www.fisheries.noaa.gov/inport/item/39739 |
| language |
[]
|
| license | https://creativecommons.org/publicdomain/zero/1.0/ |
| modified | 2019-01-01T00:00:00.000+00:00 |
| publisher |
{
"name": "National Geodetic Survey",
"@type": "org:Organization"
}
|
| references |
[
"https://www.fisheries.noaa.gov/inportserve/waf/noaa/nos/ngs/dmp/pdf/39739.pdf"
]
|
| rights | otherRestrictions, unclassified |
| spatial | -60.0,24.0,-130.0,58.0 |
| title | Geoid Height and Deflections of the Vertical Models |
