EPSG Geodetic Parameter Registry
In this document the following definitions of terms apply:
- "Registry" means the EPSG Geodetic Parameter Registry;
- "EPSG" means EPSG Geodetic Parameter Dataset;
- "OGP" means the International Association of Oil and Gas Producers, incorporated in England as a company limited by guarantee (number 1932064);
- "EPSG Facilities" means the Registry, the EPSG Dataset (published through the Registry or through a downloadable MS-Access file or through a set of SQL scripts that enable a user to create an Oracle, MySQL, PostgreSQL or other database and populate that database with the EPSG Dataset) and associated documentation consisting of the Release Notes and Guidance Notes 7.1 and 7.2
- "the data" means the geodetic parameter data and associated metadata, contained in the EPSG Dataset; it also refers to any subset of data from the EPSG Dataset.
The EPSG Facilities are published by OGP at no charge. Distribution for profit is forbidden.
The EPSG Facilities are owned by OGP. They are compiled by the Geodetic Subcommittee of the OGP from publicly available and member-supplied information.
The data may be used, copied and distributed subject to the following conditions:
DATA AND INFORMATION PROVIDED IN THE EPSG FACILITIES ARE 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.
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.
Ownership of the EPSG Dataset by OGP must be acknowledged in any publication or transmission (by whatever means) thereof (including permitted modifications).
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.
Essential 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.
|As given in EPSG Dataset||Permitted change for vendors / users to adopt|
|Change of ellipsoid defining parameters.|
|1a||Ellipsoid parameters a and b.||a and 1/f ; a and f; a and e; a and e2.|
|1b||Ellipsoid parameters a and 1/f.||a and b; a and f; a and e; a and e2.|
|Change of projection method|
|2a||Lambert Conic Conformal (1 SP) method with projection parameters φO and kO.||Lambert Conic Conformal (2 SP) method with projection parameters φ1 and φ2.|
|2b||Lambert Conic Conformal (2 SP) method with projection parameters φ1 and φ 2.||Lambert Conic Conformal (1 SP) method with projection parameters φO and kO.|
|3a||Mercator (1 SP) method with projection parameters φO and kO.||Mercator (2 SP) method with projection parameter φ1.|
|3b||Mercator (2 SP) method with projection parameter φ1.||Mercator (1 SP) method with projection parameters φO and kO.|
|4a||Hotine Oblique Mercator method with projection parameters FE and FN.||Oblique Mercator method with projection parameters EC and NC.|
|4b||Oblique Mercator method with projection parameters EC and NC.||Hotine Oblique Mercator method with projection parameters FE and FN.|
|5a||Polar Stereographic (Variant A) method with projection parameters φO and kO.||Polar Stereographic (Variant B) method with projection parameter φO and kO.|
|5b||Polar Stereographic (Variant B) method with projection parameter φF.||Polar Stereographic (Variant A) method with projection parameters φO and kO.|
|5c||Polar Stereographic (Variant A) method with projection parameters φO, kO, FE and FN.||Polar Stereographic (Variant C) method with projection parameters φF, EF and NF.|
|5d||Polar Stereographic (Variant C) method with projection parameters φF, EF and NF.||Polar Stereographic (Variant A) method with projection parameters φO, kO, FE and FN.|
|5e||Polar Stereographic (Variant B) method with projection parameters FE and FN.||Polar Stereographic (Variant C) method with projection parameters EF and NF.|
|5f||Polar Stereographic (Variant C) method with projection parameters EF and NF.||Polar Stereographic (Variant B) method with projection parameter FE and FN.|
|Note: Permitted projection method changes 2 to 5 inclusive during the parameter conversion must use the ellipsoid for the relevant projected coordinate reference system.|
|Change of transformation method|
|6a||Position Vector 7-parameter transformation method parameters RX RY and RZ.||Coordinate Frame transformation method with signs of position vector parameters RX RY and RZ reversed.|
|6b||Coordinate Frame transformation method parameters RX RY and RZ.||Position Vector 7-parameter transformation method with signs of parameters RX RY and RZ reversed.|
|7||Concatenated transformation using geocentric methods (Geocentric translations, Position Vector 7-parameter transformation, Coordinate Frame rotation).||Equivalent single geocentric transformation in which for each parameter the parameter values of the component steps have been summed.|
|Change of units|
|8||NTv2 method grid file filename.||NTv2 method grid file relative storage path with file name including removal (if necessary) of "special characters" [spaces, parentheses, etc] which are replaced by underscore characters.|
|9||Parameter value.||Convert unit to another, for example from microradian to arc-second, using conversion factors obtained from the EPSG dataset Unit table.|