To reach centimeter-level — or even better — accuracy of positioning typically requires use of
precise dual-frequency carrier phase observations.
Furthermore, these observations are usually processed using a differential GNSS (DGNSS) algorithm,
such as real time kinematic (RTK) or post-processing (PP).
Regardless of the specific differential algorithm,
however, implicit in the process is an assumption that the quality of the reference station data is consistent
with the desired level of positioning accuracy.