Reference station
As reference station one is ground station for Astro - or satellite positioning is designated, the position is accurate least known.
If the position is determined there using the measurement method customary on site, the difference to the nominal value indicates the error that occurs at this specific time. If you apply the difference as a correction value to the measuring instruments on the way, the position error can be reduced noticeably.
Astrogeodesy ( latitude and longitude determination ) is mainly concerned with errors in the time system and with the inevitable personal or instrumental sources of error (time and target errors, temperature, etc.). They are summarized under the term " personal equation " and attached to all results of the respective observer-instrument combination.
When Global Positioning System on the other hand you're working with radio - correction data , the DGPS are called data. As above, the current deviations from the target position of the reference station are determined and their proportions are assigned to each of the GPS satellites . The DGPS receivers can receive the correction data by radio and thus improve their position accuracy from about ± 10m to centimeter accuracy.