EPSG Geodesy Parameters

Version 6.6, 20 October 2004


This current release (Version 6.6) of the European Petroleum Survey Group (EPSG) Geodesy Parameters data comprises:

·        an MS Access 97 database which includes

·        tables forming the canonical v6.6 dataset;

·        browse forms and reports for viewing the data within MS Access;

·        edit/add forms for data maintenance within MS Access.

·        three SQL scripts providing a cross-platform version of the 6.6 tables.

·        a readme file (this document).

The version 6.6 release includes data updates and additional fields to assist automated selection of transformation.


Contents of this document

·        Use of the data

·        Criteria for inclusion of data

·        New in this version

·        Known limitations and/or problems in the version

·        Data availability

·        Shipping list

·        Data structure

·        Future developments

·        EPSG Geodesy Working Group


Use of the Data

1) All data pertinent to a specific coordinate reference system must be copied without modification and all related pages/records must be included;

2) All components of this data set pertinent to any given coordinate reference system must be distributed together (complete distribution of all components of the data set is preferred, but the EPSG recognises the need for a more limited distribution);

3) The data may not be distributed for profit by any third party; and

4) The original source [EPSG] must be acknowledged.

The user assumes the entire risk as to the accuracy and the use of this data. The data may be copied and distributed subject to the following conditions:


 With regard to (3) above, the data may be included within proprietary applications distributed on a commercial basis when the commerciality is based on application functionality and not on a value ascribed to the freely-distributed EPSG data.


Criteria for inclusion of data

Criteria used for material in these lists include:

·        information must be in the public domain: "private" data not released and available to the general public is not included.

·        data must be in current use by a significant number of users. This definition has been broadened to include data generated by a single user but regularly referenced by a significant number of others, including contractors and subcontractors.

·        parameters are given to the precision consistent with the original publication documents. EPSG aims for derived coordinates to be to a precision of one centimetre or better.


New to version 6.6

·         Changes as documented in Change table records through 2004.54, but with actions still remaining on some earlier change requests.

·      The addition of several items provided to assist the automatic selection of transformation, in situations where multiple exist. The data included has previously been in the dataset as free text in scope or remarks fields; this remains unchanged.

·      Succession table – populated in v6.6 only for transformations;

·      Geographic bounding box fields added to the Area table – population of these fields will be completed for the next release of the dataset;

·      Area polygon file reference field added to the Area table – not populated in v6.6;

·      Accuracy field added to Coordinate Operation table.

·      Geoid models added.

·      Geographical to geocentric conversions, previously implicit, made explicit.

Known limitations and/or problems in version 6.6

Known limits and problem areas within version 6.6 data maintenance functions are:

·        Deletion of any record with an alias does not remove the associated alias records from the alias table. In MS Access terms, there is an inability to "Enforce Referential Integrity" on links from ALIAS tables to other tables. Thus removal of aliases must be done before removal of the primary record to which they apply, or they will remain as unused residuals in the Alias table. We have added a warning to all Edit/Add forms to warn users of this problem.

·        Likewise, there is an inability to force deletion of Coordinate_Operation Parameters when a Coordinate_Operation Method is deleted. Any coordinate operation parameters (e.g., geodetic transformation parameters) that are used only in the deleted Coordinate_Operation Method will remain as unused residuals in the Coordinate_Operation Parameter table unless removed prior to deletion of the Coordinate_Operation Method. [Caution here: One should be extremely cautious in deleting Coordinate_Operation Parameter (Geodetic Transformation Parameters or Map Projection Parameters) as these are often used in various different Coordinate_Operation Methods.]

·        Similarly, if you delete a [single Geodetic] Transformation, any dependent Concatenated Operations (Concatenated Transformations) remain in the database (but clearly show that something is wrong with the now missing step.)

Problems have been reported by users who have implemented MS Access 2000 or Access 2003. Our belief is that if running Access 2000 or Access 2003 under Windows 2000, either opening in v97 read-only mode or converting to Access 2000 or Access 2003 is OK. However, problems may be encountered if running Access 2000 or Access 2003 under any other operating system. The Geodesy Working Group would appreciate user comments on any observed problems (and/or their solutions) on using the dataset under MS Access 2000, Access 2003 or other versions.


Data Availability

This version 6.6 is available for downloading at no charge from the EPSG internet web site at http://www.epsg.org (currently reflected to www.ihsenergy.com/epsg).

The User Update Utility (see EPSG Guidance Note 7 part 1) is also available for downloading at no charge as an executable.

Additional information, including detailed Guidance Notes relating to the use of the information in this geodetic database are available via the same EPSG web site, now hosted by IHS Energy for the EPSG. In particular, Guidance Note 7 part 2 (previously known as Guidance Note 7) may be useful as it provides formulae and test points for all conversions and transformation methods used in the EPSG database.

The parameter listings are "living documents" and will be updated by the EPSG from time to time, usually following meetings in April and October. Comments or suggestions for improvements may be submitted at any time.

The master dataset is available only at this site, with data supplied directly from EPSG. Users are discouraged from making the data available on alternate sites, but instead are encouraged to provide hot links to the EPSG site. This will reduce or eliminate the potential problem of users accessing versions of the data that have been superseded.

Previous versions 5.3, 6.1, 6.2.2, 6.3, 6.4 and 6.5.3 are available as superseded archived databases, along with documentation related to the mapping of the version 5 data model to the version 6 model. These older databases are not recommended for current use, but are available to users should they need to check data in a prior release, etc.

To be on an electronic mailing list to receive notification of EPSG updates at no charge, select the subscribe option on the EPSG web site. This same form may be used to send information about possible errors in the database or to request that new data be added to the EPSG database.


Shipping List

This version 6.6 data set consists of the following.

·        a downloadable file Epsg_v66.zip containing:

·        One MS Access 97 database file (EPSG_v66.mdb) which includes 21 related tables, 15 queries which provide necessary controls and inputs for the various reports and forms, 47 reports (24 on valid data plus 23 to review deprecated records) in which data is displayed in formats suitable for browsing, printing or export and 31 forms through which the data may be browsed or edited (4 welcome/navigation forms, 12 browse forms and 15 edit/add forms). Numerous subreports and subforms provide integral components and help for the various reports and forms. There are also three macros that are provided for form navigation.

·        A README file in MS Word 97-2000 & 6/95 - RTF (this file, Epsg_v66_Readme.doc and in Adobe Acrobat pdf format, Epsg_v66_Readme.pdf).

·        a downloadable file Epsg_v66sql.zip containing:

·        A Data Description Language (DDL) file which contains the SQL CREATE statements necessary to create a database equivalent to the Access on an SQL server.

·        A Data Manipulation Language (DML) file which contains the SQL INSERT statements necessary to populate a database created using the DDL file with the current contents of the dataset.

·        A second DDL file which contains the SQL ALTER statements necessary to enforce Foreign Key Constraints on the tables.

·        A README file in MS Word 97-2000 & 6/95 - RTF (this file, Epsg_v66_Readme.doc and in Adobe Acrobat pdf format, Epsg_v66_Readme.pdf).


Data Structure

See EPSG Guidance Note 7 part 1Use of the EPSG Geodetic Dataset – for a description.


EPSG Codes

EPSG has reserved the integer range 0 to 32767 for use as codes. As of Version 6.3, the EPSG also reserved the integer range from 6,000,000 to 6,999,999 for codes for geographic CRSs in explicitly described degree representations, no longer supported by EPSG. To prevent conflict with future EPSG additions to the data, users who wish to augment the data with their own information should utilise codes greater than 32768. EPSG record coding has been renumbered from previous versions to eliminate EPSG codes under 1024 in order to assist GeoTIFF compatibility.

If users wish to supplement the change table with their own entries, it is important that the user's change notice IDs be above the EPSG integer code limit of 32,767.0. For example, such an entry in the change table is required for users to deprecate any erroneous user data.


Future Developments

It is EPSG’s strategic intent to make the database web-enabled. This development is subject to the availability of resources. A proof of concept prototype is under development at http://ocean.csl.co.uk/

An interactive GIS front-end has been requested and is under review, subject to availability of resources.



EPSG Geodesy Working Group (Please post any comments or queries to the entire EPSG Geodesy Working group by using the by email to: EPSG Information and Subscription Form, which is automatically forwarded to all members of the group..)

Roger Lott (chairman)
formerly Head of Survey
BP Exploration
Chertsey Road
Sunbury on Thames
Middlesex, TW16 7LN
United Kingdom

Jim Cain
Geodetic and Survey Consultant
J Cain & Associates
12418 Stafford Springs Drive
Houston, Texas 77077

Alan Faichney
(SEG Representative)
Concept Systems, Ltd.
1 Logie Mill,
Beaverbank Business Park
Logie Green Road,
Edinburgh EH7 4HG,
United Kingdom

Walter Jardine
BP Trinidad & Tobago LLC
Queen’s Park Plaza
5-5a Queen’s Park West
PO Box 714
Port of Spain
Trinidad & Tobago, W.I.

Roel Nicolai
Senior Geodetic Consultant
Shell Technology Exploration
                and Production B.V.
Kesslerpark 1
2288 GD Rijswijk
The Netherlands

Bruno Ravanas
TOTAL - Geosciences
2 place de la Coupole –
              La defense 6
92078 Paris La Defense cedex

Mike Postle-Hacon
RPS Hydrosearch
Goldsworth House,
Denton Way,
Surrey GU21 3LG,
United Kingdom

Geir Simensen
Grenseveien 21,
N-4035 Stavanger,

Derek Salvage
ExxonMobil Exploration
UTC/DRM/DS/Geodetics &
233 Benmar
Houston, TX 77060


Version 6 Relationship Diagram: (See EPSG Guidance Note 7 part 1Use of the EPSG Geodetic Dataset – for full details on the tables and field in this relationship diagram.)