
3
Reference Systems and Coordinate
Transformations
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 ref-
erence 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 conceptual-
izing the location of the objects with respect to the common frame and with
respect to its surroundings objects. A reference system is a mathematical con-
cept for modelling the real world. This chapter starts with the