ORMs
Since the Earth is an important “reference object” in our spatial environment, many Spatial Reference Frames will consist of an Earth Reference Model plus a Coordinate System.
There are spatial reference frames which incorporate models of alternative reference objects
- E.g., a spacecraft body-centric reference as often used with the Space Shuttle, or a non-Earth planetary body, or even a celestial body
- Local Space Rectangular (LSR) uses a minimalist ORM which does not locate the CS origin, but orients the axes through specification of “up” and “forward” and a right-hand rule
In general: SRF = ORM + CS