Datum Transformation Parameters Metadata



Welcome to the Office of Geomatics metadata for Datum Transformation Parameters.

This metadata was written using the Content Standards for Digital Geospatial Metadata, June 8, 1994 version, and released by the Federal Geographic Data Committee.

1.0 Identification Information:
basic information about the data set.
2.0 Data Quality Information:
general assessment of the quality of the data set.
6.0 Distribution Information:
information about the distributor of and options for obtaining the data set
7.0 Metadata Reference Information:
information on the currentness of the metadata information, and the responsible party.

1.0 Identification Information:

1.1 Citation:
1.1.1 Originator: National Geospatial-Intelligence Agency
1.1.2 Publication Date: 1995
1.1.4 Title: Datum Transformations
1.1.6 Geospatial Data Presentation Form: database
1.1.8 Publication Information:
1.1.8.1 Publication Place: St. Louis, Missouri
1.1.8.2 Publisher: National Geospatial-Intelligence Agency
1.2 Description:
1.2.1 Abstract: This is a listing of transformation parameters, solved through the systematic determination of the discrepancies between a local non-earth centered datum and the earth centered WGS 84 datum by a movement of the ellipsoid origin (translation of X, Y, and Z axis) from the local datum origin to the WGS 84 origin. Signs can be reversed to translate the WGS 84 datum into the local datum. The parameters identified in this process are specific between each local datum and the WGS 84 datum. The process by which datum transformation parameters are developed may vary, but modern methodology requires positions common to both the local datum and the WGS 84 world wide datum.
1.2.2 Purpose: Transformation of local datums to the WGS 84 datum.
1.2.3 Supplemental Information: Each datum is assigned a specific group of transformation parameters, designed for use with the Molodensky or similar equations to compute new (transformed) geographic coordinates. Computed delta X, delta Y, and delta Z translation parameters represented by this data listing are usually satisfactory for the movement of map coordinates. Additional rotation and scale parameters are sometimes required for more precise geodetic work.
1.3 Time Period of Content:
1.3.1 Single Date/Time: 1995
1.4 Status:
1.4.1 Progress: Complete for countries with known transformations
1.4.2 Maintenance and Update Frequency: Continually developing new parameters from new datum position sets as they become available.
1.5 Spatial Domain:
1.5.1 Bounding Coordinates:
1.5.1.1 West Bounding Coordinate: -180.0 degrees
1.5.1.2 East Bounding Coordinate: 180.0 degrees
1.5.1.3 North Bounding Coordinate: 90.0 degrees
1.5.1.4 South Bounding Coordinate: -90.0 degrees
1.6 Keywords:
1.6.1 Theme:
1.6.1.1 Theme Keyword Thesaurus: DoD Glossary of Mapping, Charting, and Geodetic Terms
1.6.1.2 Theme Keyword: Transformation Parameters
1.6.2 Place:
1.6.2.1 Place Keyword Thesaurus: Appendix B NGA TR 8350.2
1.6.2.2 Place Keyword: Continent
1.7 Access Constraints: None
1.8 Use Constraints: Datum transformation parameters borrowed from NGA and/or were originally computed and verified by NGA must give credit to same.
1.9 Points of Contact:
1.9.2 Contact Organization Primary:
1.9.2.1 Contact Organization:NGA Geospatial Sciences Division
1.9.2.2 Contact Person: Datum Transformation Program Manager
1.9.3 Contact Position: Program Manager
1.9.4 Contact Address:
1.9.4.1 Address Type: mailing address
1.9.4.2 Address: 3838 Vogel Road L-41
1.9.4.3 City: St. Louis
1.9.4.4 State or Province: Missouri
1.9.4.5 Postal Code: 63010-6238
1.9.4.6 Country: United States of America
1.9.5 Contact Voice Telephone: (314)676-9124 or DSN846-9124
1.9.7 Contact Facsimile Telephone: (314)676-3113 or DSN846-3113
1.9.8 Contact Electronic Mail: gandg@nga.mil
1.9.9 Hours of Service: 0900-1500 Mon to Fri (Central Time)
1.13 Native Data Set Environment: Current parameters are listed in NGA TR 8350.2 and the most current version of the MADTRAN datum transformation program. These data sets are available to the public. Parameters also reside on the UNISYS within the DEBRUN software, and on the UNIX system under /prod/x1506. Both are accessible only to NGA personnel.
1.14 Cross Reference: Multiple Regression Equations (MRE's) Parameters are recommended only for continental size datums and for contiguous large land areas. Found in NGA Table D.1 in NGA TR 8350.2 (available for public dissemination) and on the IBM/RISC 6000.

Return to the beginning of this Metadata.

2.0 Data Quality Information:

2.1 Attribute Accuracy:
2.1.1 Attribute Accuracy Report: The accuracy of the transformation parameters is directly related to the quality and quantity of the common control points used in their derivation, the geographic distribution of the common control, the date and type of datum, the size of the area covered by the local datum, the spread and magnitude of the residuals, and the history of the local datum.
2.2 Logical Consistency Report: When the number of control points is equal to or greater than four, the spread and magnitude of the residuals in a least squares solution is the major element into the computation of accuracies for the delta X, delta Y, and delta Z transformation parameters. When the number of control points available for the transformation is less than four, the assignment of an accuracy is more arbitrary.
2.3 Completeness Report: Only data that has been made available for datum transformation is included in this product. No datum transformation parameters are included until approved by appropriate NGA channels.

Return to the beginning of this Metadata.


Point of Contact: Office of Geomatics / Coordinate Systems Analysis Branch
phone (314) 676-9124, DSN 846-9124
gandg@nga.mil

Document last modified