The meaning of accuracy is context dependent
Accuracy Or Error In The Context Of the SRM Refers To
Computational Error And Excludes Measurement Error Effects.
In geodesy a reference set of measured points is used to develop an Earth Reference Model (ERM)--a mathematical model of the Earth.
ERMs provide a mathematical framework for spatial referencing.
The amount of position error introduced by using an imperfect reference set of measured points is a major technical issue in geodesy but is outside the scope of the SRM.
In the context of the SRM, reference models of spatial objects are taken to be exact when forming spatial reference frames.
Operations on spatial reference frames may contain inaccuracies due to:
- the use of truncated power series representations,
- round off error,
- approximations made to reduce computational complexity to speed up computations.