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1. Spatial Reference Systems (SRS)

Geospatial data are stored and displayed in different coordinate systems, either as geographic (latitude / longitude) or projected coordinates. Suitable coordinate systems depend on purpose, size and location of study areas, and communication context.

Spatial reference systems are defined and available through catalogs like >http://spatialreference.org. For higher accuracy, these definitions not only include a type and parameterisation of a (map) projection, but are also based on a specified geodetic datum.

To refer to unique SRS, most software environments use EPSG coding, enabling a code like 2060 to identify UTM zone 40 coordinates based on the European Datum (ED).

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