Spatial Reference Frames
Spatial Reference Frames serve to locate coordinates in a multi-dimensional space (generally either two- or three-dimensional). They are specified in two parts:
- A geometric description (model) of a reference object embedded in (and serving to orient) that frame – referred to as an Object Reference Model (ORM)
- An Earth Reference Model (ERM) is a special case of an ORM
- A Coordinate System specifying how a tuple of values uniquely determine a location with respect to the origin of that frame. By extension, that tuple also specifies a location with respect to the reference object.
“Naked” coordinate systems have limited utility!