The Afghanistan gravity data in this report were contributed by L. D. McGinnis, Northern Illinois University, 1967; V. Erola, Isostatic Institute of the International Association of Geodesy, 1941; B. L. Ochapovskiy and D. I. Muchketov, State Geographical Society, 1933; and P. K. Zalesky, Sredne-Azjatskoe Geograficheskoe Obshehestvo, Turkestanski, 1911. Please see the external author index file report ("aif.txt") and other gravity data product files by clicking on the README line below.

DATA PRODUCTS

The gravity database is presented in Geosoft database format and is described by the two files with suffixes .gdb and .gd~. It can be converted to other formats using the free conversion software offered by this company at http://www.geosoft.com/.

1. af.txt - ASCII file of gravity data used in this report.
2. afgrav.gdb - Database of gravity data.
3. afgrav.XYZ - ASCII XYZ file of gravity data.
4. aif.txt - Author index file of gravity data contributors.
5. rbs.txt - Reference base station listing for gravity surveys.
6. computations.pdf - Gravity station data format and anomaly computations booklet.
7. readme_gravity_datafiles.pdf - Description of the data products.

PROJECTION SPECIFICATIONS

All databases, maps, grids, and xyz files in this report use the following projection specifications:

• Projection = Transverse Mercator
• Central meridian = 66 degrees E
• Base latitude = 34 degrees N
• Scale factor = 0.9996
• Semi-major ellipsoid axis = 6378137 m
• Eccentricity = 0.08181919084
• Horizontal datum = WGS 84
• Ellipsoid = WGS 84

This web site makes available to users the data products mentioned above for these surveys. To view this directory, click on the link below. To view the README file ("readme_gravity_datafiles.pdf") describing the gravity data product files, click on the README line following.

Gravity Directory

README_gravity_datafiles PDF file describing data in above directory

For more information about this report contact: Pat Hill