====== atGeoRef2 ======





===== Plugin information ===

^  Author | [[user>Aaron]] |
^  Description | This plugin allows users to edit the georeferencing settings for L3DT's project.  |
^  Menu option | '//Settings->Georeferencing//' (in L3DT v2.6 and later). |
^  Download link | Included with L3DT installer. |
^  Last update | v2.7.2.0, released 18th of April 2008. |

===== Using atGeoRef2 =====

To edit the georeferencing settings of the L3DT project, select the '//Settings->Georeferencing//' menu item in L3DT. This will open the 'georeferencing' window, shown below:

{{ :plugins:general:atgeoref2:georefdlg.png |:plugins:general:atgeoref2:georefdlg.png}}

===== Extents =====

The //extents// fields give the coordinates of the north/south/east/west edges of the project. 
  * If the //units// selection box is set to 'degrees', these extents represent the latitude/longitude of the project edges. 
  * If using the 'metres',  'feet (int.)' or 'feet (U.S.)' units __and__ the //UTM zone// checkbox is enabled, the extents represent the offsets from the origin of the UTM zone.

===== UTM zone =====

The //UTM zone// number identifies the [[wp>Universal_Transverse_Mercator_coordinate_system|Universal Transverse Mercator]] zone (1-60), if the file is in UTM. Negative zone numbers are used for the southern hemisphere.

===== EPSG datum =====

The //EPSG datum// number identifies the survey data reference point system. Valid [[http://www.epsg.org/|EPSG]] Geodetic Datum Code, which are in the range of 6001 to 6904.  If you do not care about datum, the default value is 6326, which is the WGS84 Datum.

===== Where are the settings stored? =====

The georeferencing settings will be stored in the project's [[bundydocs>l3dt:formats:specs:def.xml|map definition file]] (*.def.xml). Additionally, if the heightfield is stored in the [[http://www.vterrain.org/Implementation/Formats/BT.html|BT]] or [[bundydocs>l3dt:formats:specs:hf2|HFZ/HF2/HF2.GZ]] file formats, the georeferencing data will be stored in the relevant header sections of those files.


===== More information =====

The georeferencing system in L3DT is based on the georeferencing system used in the [[http://www.vterrain.org/Implementation/Formats/BT.html|binary terrain file format]] developed by the [[http://www.vterrain.org|Virtual Terrain Project]] (VTP).

===== Changes =====

2009/04/18 --- Released v2.7.2.0, with support for EPSG projection code.

2008/06/08 --- Released.