EPSG Geodetic Parameter Dataset

Version 6.16 – 27 June 2008: Readme file

This current release (Version 6.16) of the EPSG Geodetic Parameter Dataset comprises of data corrections and updates to the v6.15 release of April 2008. It is an interim release primarily to correct significant errors in data for the US added in the v6.15 release. The opportunity has been taken to include additional data and corrections that have been processed.

The EPSG Geodetic Parameter Dataset, or EPSG dataset, is maintained by the Geodesy Subcommittee of the Surveying and Positioning Committee of the International Association of Oil and Gas Producers (OGP).

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
• OGP Geodesy Subcommittee

Use of the Data

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

1. INFORMATION PROVIDED IN THIS DOCUMENT IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE IMPLIED WARRANTIES OF MERCHANTABILITY AND/OR FITNESS FOR A PARTICULAR PURPOSE.
2. The data may be included in any commercial package provided that any commerciality is based on value added  by the provider and not on a value ascribed to the EPSG dataset which is made available at no charge. The ownership of the EPSG dataset [OGP] must be acknowledged.
3. Subsets of information may be extracted from the dataset. Users are advised that coordinate reference system and coordinate transformation descriptions are incomplete unless all elements detailed as essential in OGP Surveying and Positioning Guidance Note 7-1 annex F are included.
4. Essental elements should preferably be reproduced as described in the dataset. Modification of parameter values is permitted as described in the table below to allow change to the content of the information provided that numeric equivalence is achieved. Numeric equivalence refers to the results of geodetic calculations in which the parameters are used, for example (i) conversion of ellipsoid defining parameters, or (ii) conversion of parameters between one and two standard parallel projection methods, or (iii) conversion of parameters between 7-parameter geocentric transformation methods.

No data that has been modified other than as permitted in these terms and conditions shall be described as or attributed to the EPSG dataset.

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. The EPSG Geodetic Parameter Dataset aims for derived coordinates to be to a precision of one centimetre or better.

New to version 6.16

• Changes as documented in Change table records through 2008.059, but with actions still remaining on some change requests.
• Significant revisions to some data for Canda and United States of America.
• Minor revisions to data for Argentina, Croatia and France
• New data for Austria and Canada.
• In descriptive text strings for sexagesimal degree values the unit text has been replaces with symbols. This brings these text strings into compliance with ISO1000 and ISO6709:2008 but is otherwise cosmetic to the geodetic data parameter content.
• Where records had EPSG as the responsible organisation, this has been changed to OGP. References to the EPSG dataset have been retained.

Known limitations and/or problems in version 6.16

Known limits and problem areas within this version of the MS Access database 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 Subcommittee 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

The dataset is available for downloading at no charge from the EPSG geodetic parameter dataset internet web site at http://www.epsg.org.

A 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 parameter dataset are available via the same web site. In particular, Guidance Note 7 part 2 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 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. 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 released since February 2002 are available as superseded archived databases. 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 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 of the dataset consists of the following.

• the EPSG Geodetic Registry c6.16, an on-line repository of the data.
• a downloadable file epsg-v6_16.zip containing:
  • One MS Access 97 database file (EPSG_v6_16.mdb) which includes 21 related tables, 18 queries which provide necessary controls and inputs for the various reports and forms, 54 reports (28 on valid data plus 26 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-v6_16-Readme.doc and in Adobe Acrobat pdf format, Epsg-v6_16-Readme.pdf).
• three downloadable files epsg-v6_16sql-mySql.zip, epsg-v6_16sql-Oracle.zip and epsg-v6_16sql-PosgreSql.zip, for mySQL, Oracle and PosgreSQL respectively, each 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-v6_16-Readme.doc and in Adobe Acrobat pdf format, Epsg-v6_16-Readme.pdf).

In addition to the MS Access database and SQL scripts of previous releases, this version 6.16 is additionally made available online through the OGP Geodetic Registry service. This supports anonymous (guest) access through which users may query and view the data and generate printable reports. It also permits the user to register for additional services, such as the export of the entire EPSG dataset as GML 3.2 dictionaries. Additionally the OGP Geodetic Registry supports access through SOAP requests, permitting geospatial software to query and retrieve geodetic parameters without human intervention.

Data Structure

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

EPSG Codes

The OGP Geodesy Subcommittee has reserved the integer range 0 to 32767 for use as codes. As of dataset version 6.3, the integer range from 6,000,000 to 6,999,999 was also reserved for codes for geographic CRSs in explicitly described degree representations, but this is no longer supported. To prevent conflict with future additions to the EPSG dataset, users who wish to augment the data with their own information should utilise codes greater than 32768.

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. Such an entry in the change table is required for users to deprecate any erroneous user data.

Future Developments

We will continue to make the dataset available as an MS Access database and through SQL scripts.

In the longer term it is intended to describe area of use polygons using GML in accordance with ISO 19136.

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

OGP Geodesy Subcommittee

(Send any comments or queries to the entire group by submitting the comment form at www.epsg.org).

OGP 2008

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

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