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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.
  • Use Constraints: If you use this data, please cite the National Geophysical Data Center and the originator of the data.
  • ID not available.
Distribution Formats
  • Binary
Ordering Instructions Ordering Instructions: Price information is available upon request. Prepay by check, money order or bank card. There is a standard handling charge, with additional costs for special handling. Orders may be placed via fax, email, regular mail or telephone. Custom Order Process: Contact Data Center for information.
Distributor Distributor information not available
Dataset No POCs available for this dataset
Time Period Unknown to Unknown
Spatial Bounding Box Coordinates
N: 53
S: 24
E: -66
W: -130
Spatial Coverage Map
Documentation links not available.
Publication Dates
  • publication: 1999-01-01
Edition 1999 Edition
Dataset Progress Status
  • Complete
Data Update Frequency Irregular
Purpose To provide easy access to global and regional gravity data and related models for scientific studies.
Dataset Citation
  • Use Constraints: If you use this data, please cite the National Geophysical Data Center and the originator of the data.
Originator(s)
  • Dataset contact information not available
Publisher(s)
    Theme keywords
    • 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
    Uncontrolled Keywords
    • Absolute Gravity
    • Bouguer Gravity
    • Free Air Anomaly
    • Gridded Gravity
    • Land Gravity
    • Observed Gravity
    Place keywords
    • Continent>North America>United States of America
    Keywords
      Keywords
        Use Constraints
        • Use Constraints: If you use this data, please cite the National Geophysical Data Center and the originator of the data.
        Access Constraints
        • Access Constraints: None
        Fees
        • Depends on the data set
        Lineage information for: dataset
        Processing Steps
        • All data were processed by the source before being forwarded to the National Geophysical Data Center
        Source Datasets
        • U.S. North-South Deflections (DEFLEC96)
          Last Modified: 2017-09-25
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