What is a Spatial Reference Frame?
A spatial reference frame (SRF) consists of
- an Object Reference Model (ORM) and
- a coordinate system, where a coordinate in the coordinate system uniquely identifies a point with respect to the ORM.
The definition of a(n) SRF includes the specification of the relationship of the coordinate system and the ORM by defining the location of the origin of the coordinate system and the orientation and position of its axes with respect to the ORM.
Example of an ORM: An ellipsoid representing the Earth.
For further details, see the SRM tutorial.
Definition from ISO 18026, WD 5 - SRM Standard