GPS·C, short for GPS Correction, was a Differential GPS data source for most of Canada maintained by the Canadian Active Control System, part of Natural Resources Canada. When used with an appropriate receiver, GPS·C improved real-time accuracy to about 1–2 meters, from a nominal 15 m accuracy.
Real-time data was collected at fourteen permanent ground stations spread across Canada, and forwarded to the central station, "NRC1", in Ottawa for processing.
Visiting the external webpage for this service on 2011-11-04, there is only a note saying that the service had been discontinued on 2011-04-01. There is a PDF link on that page to possible alternatives.
GPS·C information was broadcast Canada-wide on MSAT by the CDGPS, short for Canada-Wide DGPS Correction Service. CDGPS required a separate MSAT receiver, which output correction information in the RTCM format for input into any suitably equipped GPS receiver. The need for a separate receiver made it less cost-effective than solutions like WAAS or StarFire, which receive their correction information using the same antenna and receiver.
|Station name||Location||Operational Date||Coordinates|
|ALBH||Canadian Forces Base, Esquimalt, British Columbia (near Victoria, British Columbia)||1 May 1992|
|ALGO||Algonquin Space Complex, Algonquin Provincial Park, Ontario||1 January 1991|
|CHUR||Geological Survey of Canada regional seismic station, Churchill, Manitoba||1 April 1993|
|DRAO||Dominion Radio Astrophysical Observatory, Penticton, British Columbia||1 February 1991|
|EUR2||New Environment Canada Weather Station building, Eureka, Nunavut||9 October 2005|
|FRDN||Hugh John Fleming Forestry Complex, near the University of New Brunswick in Fredericton, New Brunswick||1 February 2003|
|HLFX||Bedford Institute of Oceanography, Dartmouth, Nova Scotia||19 December 2001|
|NRC1||Institute for National Measurement Standards, National Research Centre, Ottawa, Ontario||1 April 1995|
|PRDS||Dominion Observatory in Priddis, Alberta (near Calgary, Alberta)||7 January 1997|
|SCH2||Transport Canada radio telecommunication facility, Schefferville, Quebec||29 June 1997|
|STJO||Geological Survey of Canada (NRCan) geomagnetic observing station, St. John's, Newfoundland||1 May 1992|
|WHIT||Whitehorse, Yukon||1 June 1996|
|WINN||NavCanada Winnipeg Area Control Centre building, Winnipeg, Manitoba||9 January 1997|
|YELL||Yellowknife, Northwest Territories||1 January 1991|
On April 9, 2010, it was announced that the service would be discontinued by March 31, 2011. The service was decommissioned on March 31, 2011 and finally terminated on April 1, 2011, at 9:00 EDT.