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.

Data and Resources

Field Value
accessLevel public
accrualPeriodicity irregular
bureauCode {006:48}
catalog_@context https://project-open-data.cio.gov/v1.1/schema/catalog.jsonld
catalog_conformsTo https://project-open-data.cio.gov/v1.1/schema
catalog_describedBy https://project-open-data.cio.gov/v1.1/schema/catalog.json
identifier gov.noaa.ngdc.mgg.geophysics:G01431
language {en-US}
modified 1999-01-01
old-spatial {"type": "Polygon", "coordinates": [[[-119.0, 14.0], [-75.0, 14.0], [-75.0, 33.0], [-119.0, 33.0], [-119.0, 14.0]]]}
programCode {006:059}
publisher DOC/NOAA/NESDIS/NCEI > National Centers for Environmental Information, NESDIS, NOAA, U.S. Department of Commerce (Point of Contact)
resource-type Dataset
source_datajson_identifier true
source_hash 427320195fbf5544000ad631edd12b7107d5df30
source_schema_version 1.1
spatial {"type": "Polygon", "coordinates": [[[-119.0, 14.0], [-75.0, 14.0], [-75.0, 33.0], [-119.0, 33.0], [-119.0, 14.0]]]}
Groups
  • AmeriGEOSS
  • National Provider
  • North America
Tags
  • absolute-gravity
  • amerigeo
  • amerigeoss
  • bouguer-gravity
  • ckan
  • continentnorth-americamexico
  • doc-noaa-nesdis-ncei-national-centers-for-environmental-information
  • doc-noaa-nesdis-ngdc-national-geophysical-data-center
  • earth-sciencesolid-earthgeodetics-gravitycontrol-surveys
  • earth-sciencesolid-earthgeodetics-gravitygravitational-field
  • earth-sciencesolid-earthgeodetics-gravitygravity
  • earth-sciencesolid-earthgeodetics-gravityreference-systems
  • earth-sciencesolid-earthgeodetics-gravitysatellite-orbits
  • free-air-anomaly
  • geo
  • geoss
  • gridded-gravity
  • icsu-wds-international-council-for-science-world-data-system
  • land-gravity
  • national
  • nesdis
  • noaa
  • north-america
  • observed-gravity
  • u-s-department-of-commerce
  • united-states
isopen False
license_id notspecified
license_title License not specified
maintainer Susan McLean
maintainer_email Susan.McLean@noaa.gov
metadata_created 2025-11-21T19:57:42.735639
metadata_modified 2025-11-21T19:57:42.735642
notes 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.
num_resources 6
num_tags 26
title Mexico East-West Deflections (DMEX97)