Create a coordinate system

Create a new coordinate system. A coordinate system defines the XY-coordinates or LatLon-coordinates in your maps. A coordinate system is directly used by point, segment and polygon maps; a raster map uses a georeference which uses a coordinate system. One coordinate system can be used by many maps.

This dialog box appears:

when from the File menu of the Main window, you choose the Create Coordinate System command, or
when you double-clicked the New CrdSys item in the Operation-list,
when you clicked the create coordinate system button in the Polygon Map Properties, Segment Map Properties, Point Map Properties or the Georeference Properties sheet,
when you clicked the create coordinate system button in a Create Georeference dialog box,
when you clicked the create coordinate system button in the dialog box of the Transform polygon map, Transform segment map, Transform point map operation.

Dialog box options:

Coordinate system name:	Type a new name for the coordinate system. As one coordinate system is used for all maps with the same projection, it is advised to enter a coordinate system name that applies to all maps (the name of the country, region, project, etc.).
Description:	Optionally, type a description for the coordinate system. The description is visible on the status bar of the Main window when moving the mouse pointer over the coordinate system in the Catalog.
CoordSys Boundary Only:	Select Coordinate System Boundary Only when you want to define XY-coordinates by only specifying the outer boundaries of a study area. This type of coordinate system should only be used when you are sure that you will not use projections at all. The Edit Coordinate System Boundary Only dialog box will appear.
CoordSys Projection:	Select Coordinate System Projection when you want to define XY-coordinates by specifying the outer boundaries of a study area and when you want to have the possibility to add projection information, ellipsoid information or datum information. You can add the projection information later on or right away. The Edit Coordinate System Projection dialog box will appear. This type of coordinate system can be used to define XY-coordinates of a study area (as coordsys boundary only) but when you know the projection in which your map(s) are drawn, you can add this information. You will then see XY-coordinates and LatLon coordinates on the status bar of a map window when you display the map and you can transform your maps to a coordinate system with another projection. You can also use this option to create a couple of coordinate systems with different projections in which you would like to present your data later on.
CoordSys LatLon:	Select Coordinate System LatLon when you want to define LatLon- coordinates by only specifying the outer boundaries of a study area in LatLon. Optionally, you can add ellipsoid information and datum information. This type of coordinate system can be used when you obtained data in LatLon. The Edit Coordinate System LatLon dialog box will appear.
CoordSys Formula:	Select Coordinate System Formula when you obtained data which is using different XY-coordinates than the coordinate system of your project, and when you know the relation between the two coordinate systems. The Edit Coordinate System Formula dialog box will appear. This type of coordinate system can be created for maps which use artificial coordinates, for instance maps starting at (0,0), or maps digitized in millimeters. You have to specify parameters like origin shift, scale, rotation, etc. or you can type complete formulas. To change the XY-coordinates of a vector map with artificial coordinates, perform a Transform operation.
Related coordsys:	Select the coordinate system with the correct coordinates.
CoordSys Tiepoints:	Select Coordinate System Tiepoints when you obtained data which is using different XY-coordinates than the coordinate system of your project, and when you do not know the relation between the two coordinate systems. This type of coordinate system can be created for maps which use artificial coordinates, for instance maps starting at (0,0) or maps digitized in millimeters. The Coordinate System Tiepoint editor will be opened in which you can add tiepoints to the selected background map.
Related coordsys:	Select the coordinate system with the correct coordinates.
Background map:	Select a point, segment or polygon map (with 'wrong' coordinates) that will be displayed in the Tiepoint editor and on which you will position the tiepoints. The background map will directly use the coordinate system which you are creating.

Tips:

When you create a coordinate system by using the File menu in the Main window or by double-clicking the New Coordinate System item in the Operation-tree or the Operation-list, the Create Coordinate System dialog box as described above will appear. When finished creating the coordinate system, you have to make sure that the newly created coordinate system is linked to ALL maps that should use that coordinate system: you have to edit the properties of these maps.
When you create a coordinate system by using File menu in a map window, the Create Coordinate System (in map window) dialog box will appear. You can only create a coordsys formula, a coordsys tiepoints, a coordsys direct linear or a coordsys orthophoto. A question will be asked whether the newly created coordinate system should be directly linked to the maps which are displayed in the map window. You should answer the question with Yes; then you do not have to edit the properties of these maps.
Once you have created a correct coordinate system, it is advised to make it read-only in the Coordinate System Properties sheet.
To change the coordinates of maps from one coordinate system to another coordinate system, use the Transform Points, Transform Segments or Transform Polygons operation. To transform coordinates of raster maps from one georeference to another georeference (which has for instance another coordsys), use the Resample operation.