Transformations describe a mapping between two coordinate systems. Moslty, both coordinate systems have the same type. Transformation parameters are determined a posteriori by measurements and have an accuracy.

Transformations have geometric conditions like:

Often transformation methods are chosen based on the conditions on the geometric properties.

When applying transformations to coordinate reference systems, in the most cases the datum changes.

[Voser 2007]

[Voser 2007]

[Voser 2007]