Manually editing the EPSG database

Warning

These instructions are very advanced, and are here mainly for the curious who want to know details about the EPSG database subsystem.

To define a custom projection, edit the EPSG.sql file, which is used to create the cached EPSG database.

  1. Navigate to the WEB-INF/lib directory

  2. Uncompress the gt2-epsg-h.jar file. On Linux, the command is:

    jar xvf gt2-epsg-h.jar

  3. Open org/geotools/referencing/factory/epsg/EPSG.sql with a text editor. To add a custom projection, these entries are essential:

    1. An entry in the EPSG_COORDINATEREFERENCESYSTEM table:

      (41111,'WGC 84 / WRF Lambert',1324,'projected',4400,NULL,4326,20000,NULL,NULL,'US Nat. scale mapping.','Entered by Alex Petkov','Missoula Firelab WRF','WRF','2000-10-19','',1,0),

      where:

      • 1324 is the EPSG_AREA code that describes the area covered by my projection

      • 4400 is the EPSG_COORDINATESYSTEM code for my projection

      • 20000 is the EPSG_COORDOPERATIONPARAMVALUE key for the array that contains my projection parameters

    2. An entry in the EPSG_COORDOPERATIONPARAMVALUE table:

      (20000,9802,8821,40,'',9102),    //latitude of origin
(20000,9802,8822,-97.0,'',9102), //central meridian
(20000,9802,8823,33,'',9110),    //st parallel 1
(20000,9802,8824,45,'',9110),    //st parallel 2
(20000,9802,8826,0.0,'',9001),   //false easting
(20000,9802,8827,0.0,'',9001)    //false northing

      where:

      • 9802 is the EPSG_COORDOPERATIONMETHOD key for the Lambert Conic Conformal (2SP) formula

    3. An entry in the EPSG_COORDOPERATION table:

      (20000,’WRF Lambert’,’conversion’,NULL,NULL,’’,NULL,1324,’Used for weather forecasting.’,0.0,9802,NULL,NULL,’Used with the WRF-Chem model for weather forecasting’,’Firelab in Missoula, MT’,’EPSG’,’2005-11-23’,’2005.01’,1,0)

      where:

      • 1324 is the EPSG_AREA code that describes the area covered by my projection

      • 9802 is the EPSG_COORDOPERATIONMETHOD key for the Lambert Conic Conformal (2SP) formula

Note

Observe the commas. If you enter a line that is at the end of an INSERT statement, the comma is omitted (make sure the row before that has a comma at the end). Otherwise, add a comma at the end of your entry.

  1. After all edits, save the file and exit.

  2. Compress the gt2-epsg-h.jar file. On Linux, the command is:

    jar -Mcvf gt2-epsg-h.jar META-INF org

  3. Remove the cached copy of the EPSG database, so that can be recreated. On Linux, the command is:

    rm -rf /tmp/Geotools/Databases/HSQL

  4. Restart GeoServer.

The new projection will be successfully parsed. Verify that the CRS has been properly parsed by navigating to the SRS List page in the Web administration interface.

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