A coordinate reference system (CRS) is selected every time data is opened in CARIS. CRS information can be viewed using the Select Coordinate Reference System dialog box.
Information in the dialog box is read from an inter-related set of files that control coordinate information in CARIS. (For more information on the Select Coordinate Reference System dialog box, see CARIS help).
These files are located in
C:\Program Files\CARIS\Caris\<version>\system.
Most files can be reconfigured for custom copies and the application can be pointed to these modified files. The following table lists the files responsible for projections and reprojections in CARIS.
File | Description |
| A database file that contains EPSG coordinate reference systems and coordinate transformations developed by the International Association of Oil and GAS Producers (IOGP). CARIS supports the following CRS types from the EPSG database: Projected, Geodetic, Horizontal Compound, and Engineering. This file should never be modified. For more information on available Coordinate Reference Systems and transformations, see IOGP website at |
| The map definition file contains a list of projections and definitions not included in epsg.db. This file can be copied and modified. Do not modify the original file. For more information, see Map Definition File. |
| The datum file contains a list of ellipsoid parameters (semi-axes; X, Y, Z) and coordinate transformation parameters (shifts from and rotations about the geocentre) required to make the axis of the ellipsoid coincide with the WGS 84 ellipsoid. This file uses a Coordinate Frame Rotation transformation for on-the-fly reprojections. The file can be copied and modified. Do not modify the original file. For more information, see Datum File. |
| The CRS binding file binds an EPSG CRS to a coordinate transformation. The coordinate transformations can be in epsg.db or the datum.dat. The CRS must be from EPSG. For more information, see CRS Binding File. |
grid shift datum transformations | Grid shift datum transformations are a group of files to perform datum transformations. All system files distributed with the application are located in this folder:
Additional files can be acquired. For more information, see Grid Transformations. |