Coordinate reference systems

Coordinate reference systems are used to project the three-dimensional Earth onto two-dimensional maps. There are many such models for expressing locations on Earth in a coordinate system. Spotfire supports more than you can ever hope to need, but the geocoding data tables provided by Spotfire are expressed in the coordinate reference system EPSG:4326 - WGS84, which we will use for all the geographic examples in this chapter. Don't worry about what this means for now; you can always go and look it up later.