Many SRF Realizations
And each has a customer-base
for whom it is the preferred (if not only) choice ...
There are a potentially infinite set of spatial reference frames based on the same orthonormal coordinate system with the same relationships to an ORM, but with differing ORMs
- e.g., as defined by different ellipsoid of revolution ORS parameters
Or which may share a common ORM, but which have different relationships between the orthonormal coordinate system and the ORM
- e.g., celestiocentric (CC) and Local Tangent Plane (LTP)
Each of these spatial reference frames is unique, unambiguous, and can be exactly related to the others