Definition: Differential GPS (DGPS)
UN - Geographic Information Systems
The set of techniques used to improve the accuracy of coordinates captured with a GPS by calculating the signal error (offset) for a second GPS receiver (the base station) at a location which has been precisely and accurately determined. The correction factor is applied to the coordinates captured by the mobile unit, either in real time or in post-processing mode (i.e., using a database of time referenced correction information). In some parts of the world, differential correction information is broadcast continuously from a set of permanent base stations.
United Nations, "Handbook on Geospatial Infrastructure in Support of Census Activities", Department of Economic and Social Affairs, Statistics Division, Studies in Methods, Series F No. 103, New York, 2009