The NGS Absolute Gravity data (78 stations) was received in July 1993. Principal gravity parameters include Gravity Value, Uncertainty, and Vertical Gradient. The data are randomly spaced worldwide.

The SEG gravity data are the product of the ad hoc Gravity Anomaly Map (GAM) Committee, sponsored by the Society of Exploration Geophysicists (SEG) and the U.S. Geological Survey (USGS). The committee co-chairmen were Paul L. Lyons and Norbert W. O'Hara.

These grid files were used to produce gravity and basin depth maps of the Basin and Range Province, western United States. The maps show gravity values and modeled basin depths in this area. The data were compiled by the U.S. Geological Survey, Denver, Colorado. This data base was received in June, 1995. For further information see the readme.txt file in this directory(data\grids\basinrng), and the "Gravity and Basin-Depth Maps of the Basin and Range Province, Western United States", by R.W. Saltus and R.C. Jachens, Map GP-1012.

These grid files were used to produce gravity and basin depth maps of the Basin and Range Province, western United States. The maps show gravity values and modeled basin depths in this area. The data were compiled by the U.S. Geological Survey, Denver, Colorado. This data base was received in June, 1995. For further information see the readme.txt file in this directory (data\grids\basinrng), and the "Gravity and Basin-Depth Maps of the Basin and Range Province, Western United States", by R.W. Saltus and R.C. Jachens, Map GP-1012.

The gravity station data (5,363 records) were compiled by the U. S. Geological Survey. This data base was received on February 23, 1993. Principal gravity parameters include observed gravity and Free-air anomalies. The observed gravity values are believed referenced to the International Gravity Standardization Net 1971 (IGSN 71). It is also believed the gravity anomaly computation uses the Geodetic Reference System 1967 (GRS 67) theoretical gravity formula.

The dgrav gridded data set was produced by NGDC by regridding the Decade of North American (DNAG) 6-km gravity grid of N. America. A grid cell dimension of 2.5 minutes of longitude and latitude was used in this regridding process. In order to facilitate the comparison of the various regridded data, a geodetic reference system was used as the most suitable common coordinate frame.

The gravity station data (1,037 records) were compiled by Doctor Stierman. This data base was received in June 1992. Principal gravity parameters include Free-Air Anomalies and both Simple Bouguer Anomalies (no terrain correction applied), and Complete Bouguer Anomalies (a terrain correction has been applied). The observed gravity values are referenced to the U.S.G.S. gravity base station network or to the State of Ohio gravity base station network. The 1930 International Gravity Formula was used to calculate theoretical gravity. The data are randomly distributed within north western Ohio and a portion of northwestern West Virginia.

The data (15,904 records documenting 9,090 worldwide gravity base stations) were gathered by various governmental organizations (and academia) using a variety of methods. This data base was received in August 1993. Principal gravity parameters include station id and observed gravity. The observed gravity values are referenced to the International Gravity Standardization Net 1971 (IGSN 71) and the gravity anomalies are computed using the World Geodetic System 1984 (WGS 84) theoretical gravity formula. The spatial resolution of the data is randomly distributed throughout the world. Note that the dmanet93.bin file contains only the station name for each of the 9,090 stations. The complete listing for each station(including any supplementary records), are contained in the ASCII file named dmanet93.asc.

GEOSAT DATA: Gridded Gravity Anomalies for the Southern Ocean