U.S. North-South Deflections (DEFLEC96)

This 2' surface deflection of the vertical grid for the conterminous United States is the DEFLEC96 model. The computationused 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)). The deflections were obtained by numerical differentiation of cubic spline models along the meridians of the GEOID96 grid. The gravity values are based on theInternational Gravity Standardization Net 1971 (IGSN71). The deflections are referred to the Geodetic Reference System 1980 (GRS80) ellipsoidal normals. The deflections of the vertical incorporate the reference system relationship between NAD 83(86) and ITRF94(1996.0), the datum offset of NAVD 88, and thecontributions from 2951 GPS on leveled benchmarks. The curvature of the plumb line correction has been applied. http://www.ngs.noaa.gov/DEFLEC/deflec.html 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:G01442
language {en-US}
modified 1999-01-01
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]]]}
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 07fdfd319e60ec00d5795ed5855a078b5b1dc0b3
source_schema_version 1.1
spatial {"type": "Polygon", "coordinates": [[[-130.0, 24.0], [-66.0, 24.0], [-66.0, 53.0], [-130.0, 53.0], [-130.0, 24.0]]]}
Groups
  • AmeriGEOSS
  • National Provider
  • North America
Tags
  • absolute-gravity
  • amerigeo
  • amerigeoss
  • bouguer-gravity
  • ckan
  • continentnorth-americaunited-states-of-america
  • 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 2025-11-20T17:16:02.971060
metadata_modified 2025-11-20T17:16:02.971064
notes This 2' surface deflection of the vertical grid for the conterminous United States is the DEFLEC96 model. The computationused 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)). The deflections were obtained by numerical differentiation of cubic spline models along the meridians of the GEOID96 grid. The gravity values are based on theInternational Gravity Standardization Net 1971 (IGSN71). The deflections are referred to the Geodetic Reference System 1980 (GRS80) ellipsoidal normals. The deflections of the vertical incorporate the reference system relationship between NAD 83(86) and ITRF94(1996.0), the datum offset of NAVD 88, and thecontributions from 2951 GPS on leveled benchmarks. The curvature of the plumb line correction has been applied. http://www.ngs.noaa.gov/DEFLEC/deflec.html 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 U.S. North-South Deflections (DEFLEC96)