FME ships with over 5000 coordinate systems based on a variety of different projections, ellipsoids, and datums. Given that amount of choice working with coordinate sytems can be a daunting task. Explore our documentation and knoweldge base articles which walk you through the basics and outline the gotchas.

Overview of Coordinate Systems in FME

All FME features know about their coordinate system and, therefore, their location on the earth. An FME coordinate system contains a complete mathematical model of the conversion between a specific location on the earth and a set of coordinates. Coordinate system definitions are specified by a set of parameters that define this mathematical model, including the earth model (ellipsoid or datum), the units used to measure the coordinates, the projection type, and any parameters specific to the projection type.

When an FME reader knows its coordinate system, the FME creates a coordinate system to match the input data specification and tags each feature read with this system name. However, a majority of formats do not explicitly store the coordinate system. In such cases, mapping file directives are used to supply coordinate system information.