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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.
Complete Metadata
| @type | dcat:Dataset |
|---|---|
| accessLevel | non-public |
| contactPoint |
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"@type": "vcard:Contact",
"hasEmail": "mailto:brian.meyer@noaa.gov"
}
|
| describedByType | application/octet-steam |
| description | 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. |
| distribution |
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|
| identifier | gov.noaa.ngdc.mgg.geophysics:G01431 |
| issued | 1999-01-01T00:00:00.000+00:00 |
| keyword |
[
"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",
"ICSU-WDS > International Council for Science - World Data System",
"Continent>North America>Mexico",
"DOC/NOAA/NESDIS/NCEI > National Centers for Environmental Information, NESDIS, NOAA, U.S. Department of Commerce",
"DOC/NOAA/NESDIS/NGDC > National Geophysical Data Center, NESDIS, NOAA, U.S. Department of Commerce"
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|
| language |
[]
|
| license | https://creativecommons.org/publicdomain/zero/1.0/ |
| modified | 1999-01-01T00:00:00.000+00:00 |
| publisher |
{
"name": "NOAA National Centers for Environmental Information",
"@type": "org:Organization"
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|
| rights | otherRestrictions, otherRestrictions |
| spatial | -75.0,14.0,-119.0,33.0 |
| title | Mexico East-West Deflections (DMEX97) |
