About Custom Coordinate Systems

A custom coordinate system is a Shared Resource that defines one or more coordinate systems that are not included in FME by default.

FME is used in many different countries around the world, and it is also used with a variety of custom datasets within each country. However, sometimes FME’s Coordinate System Gallery doesn't include the coordinate systems that are being used. In these cases, you will have to define the coordinate systems before FME can use them.

Adding a Custom Coordinate System

To add a custom coordinate system, create a new .fme file that defines one, and save it to %USER%\Documents\FME\CoordinateSystems, or a shared folder (defined in Tools > FME Options > Default Paths > Shared FME Folders).

You must restart Workbench before FME can recognize the custom coordinate system.

The custom coordinate system will appear in the columns of the Coordinate System Gallery.

The projection and units of your source data are not predefined within FME, so, to define them, you must add the following lines:

Coordinate System Definition Lines Additional Information

COORDINATE_SYSTEM_DEF <coordsysname>  \


PROJ <projType>  \

Table of projection types

UNIT <unitName> \

Table of predefined units

(DT_NAME <datumName> | EL_NAME <ellipName>) \

Table of predefined datums and predefined ellipsoids. Note that each coordinate system definition must specify either a datum or ellipsoid.

[<parameter> <value>]+  \


[DESC_NM <descriptive_name>] \


[GROUP <group_name>]  \

Tip: Defining a unique group name allows you to sort coordinate systems by the "Group" column in the Coordinate System Gallery.

[QUAD <quadrant>] \

Quadrant definition

[SOURCE <source>] \


[ZERO_X <zero_x>] \  


[ZERO_Y <zero_y>] \


Parameter Descriptions

The parameters above are described in Coordinate System Parameters.