ABSTRACT
If geodesy is about modelling the Earth’s surface and shape, the coordinate system connects the model produced by geodesic modelling to a frame of reference for measurement. The coordinate system or reference frame or frame of reference is a mathematical concept for imparting order to a distributed set of objects in sea, space or terrain. The frame of reference helps in conceptualizing the location of the objects with respect to the common frame and with respect to its surroundings objects. A reference system is a mathematical concept for modelling the real world. This chapter starts with the mathematical definition of a coordinate reference system. Then we discuss different types of coordinate systems and their characterization, since the mathematical and computing aspects of GIS used to represent a point in the coordinate system are quite intriguing. Map projection and coordinate system are interrelated mathematically. A discussion on coordinate systems and map projections can be found in Maling [35].
