GPS·C, short for GPS Correction, is a Differential GPS

Differential GPS

Differential Global Positioning System is an enhancement to Global Positioning System that provides improved location accuracy, from the 15-meter nominal GPS accuracy to about 10 cm in case of the best implementations....

 data source for most of Canada

Canada

Canada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean...

 maintained by the Canadian Active Control System, part of Natural Resources Canada

Natural Resources Canada

The Department of Natural Resources , operating under the FIP applied title Natural Resources Canada , is the ministry of the government of Canada responsible for natural resources, energy, minerals and metals, forests, earth sciences, mapping and remote sensing...

. When used with an appropriate receiver, GPS·C improves real-time accuracy to about 1-2 meters, from a nominal 15 m accuracy.

Real-time data is collected at fourteen permanent ground stations spread across Canada, and forwarded to the central station, "NRC1", in Ottawa

Ottawa

Ottawa is the capital of Canada, the second largest city in the Province of Ontario, and the fourth largest city in the country. The city is located on the south bank of the Ottawa River in the eastern portion of Southern Ontario...

 for processing.

Visiting the external webpage for this service on 20111104, there is only a note saying that the service had been discontinued on 20110401. There is a PDF link on that page to possible alternatives.

CDGPS

GPS·C information is currently broadcast Canada-wide on MSAT

MSAT

MSAT, short for Mobile Satellite, is a satellite-based mobile telephony service developed by the National Research Council of Canada. Supported by a number of companies in the US and Canada, MSAT hosts a number of services, including the broadcast of CDGPS signals...

 by the CDGPS, short for Canada-Wide DGPS Correction Service. CDGPS requires a separate MSAT receiver, which outputs correction information in the RTCM

RTCM

The Radio Technical Commission for Maritime Services is an international standards organization.The Radio Technical Commission for Maritime Services is an international non-profit scientific, professional and educational organization. RTCM members are organizations that are both non-government...

 format for input into any suitably equipped GPS receiver. The need for a separate receiver makes it less cost-effective than solutions like WAAS

Wide Area Augmentation System

The Wide Area Augmentation System is an air navigation aid developed by the Federal Aviation Administration to augment the Global Positioning System , with the goal of improving its accuracy, integrity, and availability...

 or StarFire

StarFire (navigation system)

StarFire is a wide-area differential GPS developed by John Deere's NavCom and precision farming groups. StarFire broadcasts additional "correction information" over satellite L-band frequencies around the world, allowing a StarFire-equipped receiver to produce position measurements accurate to well...

, which receive their correction information using the same antenna and receiver.

CDGPS Reference Stations

Station name	Location	Operational Date	Coordinates
ALBH	Canadian Forces Base, Esquimalt, British Columbia Esquimalt, British Columbia The Township of Esquimalt is a municipality at the southern tip of Vancouver Island, in British Columbia, Canada. It is bordered to the east by the provincial capital, Victoria, to the south by the Strait of Juan de Fuca, to the west by Esquimalt Harbour and Royal Roads, to the northwest by the...  (near Victoria, British Columbia Victoria, British Columbia Victoria is the capital city of British Columbia, Canada and is located on the southern tip of Vancouver Island off Canada's Pacific coast. The city has a population of about 78,000 within the metropolitan area of Greater Victoria, which has a population of 360,063, the 15th most populous Canadian... )	May 1992	48°23′23.2"N 123°29′14.8"W
ALGO	Algonquin Space Complex, Algonquin Provincial Park Algonquin Provincial Park Algonquin Provincial Park is a provincial park located between Georgian Bay and the Ottawa River in Central Ontario, Canada, mostly within the Unorganized South Part of Nipissing District. Established in 1893, it is the oldest provincial park in Canada. Additions since its creation have increased... , Ontario Ontario Ontario is a province of Canada, located in east-central Canada. It is Canada's most populous province and second largest in total area. It is home to the nation's most populous city, Toronto, and the nation's capital, Ottawa....	January 1991	45°57′20.8"N 78°4′16.9"W
CHUR	Geological Survey of Canada regional seismic station, Churchill, Manitoba Churchill, Manitoba Churchill is a town on the shore of Hudson Bay in Manitoba, Canada. It is most famous for the many polar bears that move toward the shore from inland in the autumn, leading to the nickname "Polar Bear Capital of the World" that has helped its growing tourism industry.-History:A variety of nomadic...	April 1993	58°45′32.6"N 94°5′19.4"W
DRAO	Dominion Radio Astrophysical Observatory, Penticton, British Columbia Penticton, British Columbia Penticton is a city in the Okanagan Valley of the Southern Interior of British Columbia, Canada, situated between Okanagan and Skaha Lakes. Its 2010 population was 37,721 .-Name origin:...	February 1991	49°19′21.4"N 119°37′27.9"W
EUR2	New Environment Canada Weather Station building, Eureka, Nunavut Eureka, Nunavut Eureka is a small research base on Fosheim Peninsula, Ellesmere Island, Qikiqtaaluk Region, in the Canadian territory of Nunavut. It is located on the north side of Slidre Fiord, which enters Eureka Sound farther west. It is the second-northernmost permanent research community in the world. The...	October 9, 2005	79°59′20.2"N 85°56′15.2"W
FRDN	Hugh John Fleming Forestry Complex, near the University of New Brunswick in Fredericton, New Brunswick Fredericton, New Brunswick Fredericton is the capital of the Canadian province of New Brunswick, by virtue of the provincial parliament which sits there. An important cultural, artistic, and educational centre for the province, Fredericton is home to two universities and cultural institutions such as the Beaverbrook Art...	February 2003	45°56′0.6"N 66°39′35.6"W
HLFX	Bedford Institute of Oceanography Bedford Institute of Oceanography The Bedford Institute of Oceanography is a major Canadian government ocean research facility located in Dartmouth in the Halifax Regional Municipality in Nova Scotia. The Bedford Institute of Oceanography is the largest ocean research station in Canada... , Dartmouth, Nova Scotia Dartmouth, Nova Scotia Dartmouth founded in 1750, is a community and planning area of the Halifax Regional Municipality, Nova Scotia. Located on the eastern shore of Halifax Harbour, Dartmouth has been nicknamed the City of Lakes after the large number of lakes located in the city.On April 1, 1996, the provincial...	December 19, 2001	44°41′0.7"N 63°36′40.6"W
NRC1	Institute for National Measurement Standards, National Research Centre, Ottawa, Ontario	April 1995	45°27′15.0"N 75°37′25.8"W
PRDS	Dominion Observatory in Priddis, Alberta (near Calgary, Alberta)	January 7, 1997	50°52′16.8"N 114°17′36.5"W
SCH2	Transport Canada radio telecommunication facility, Schefferville, Quebec Schefferville, Quebec Schefferville is a town in the Canadian province of Quebec. Schefferville is in the heart of the Naskapi and Innu territory in northern Quebec, less than 2 km from the border with Labrador on the north shore of Knob Lake. The town has an incorporated area of . It is located within the...	June 29, 1997	54°49′55.5"N 66°49′57.4"W
STJO	Geological Survey of Canada (NRCan) geomagnetic observing station, St. John's, Newfoundland	May 1992	47°35′42.8"N 52°40′39.9"W
WHIT	Whitehorse, Yukon Whitehorse, Yukon Whitehorse is Yukon's capital and largest city . It was incorporated in 1950 and is located at kilometre 1476 on the Alaska Highway in southern Yukon. Whitehorse's downtown and Riverdale areas occupy both shores of the Yukon River, which originates in British Columbia and meets the Bering Sea in...	June 1996	60°45′01.8"N 135°13′19.5"W
WINN	NavCanada Winnipeg Area Control Centre building, Winnipeg, Manitoba	January 9, 1997	49°54′02.1"N 97°15′34.1"W
YELL	Yellowknife, Northwest Territories Yellowknife, Northwest Territories Yellowknife is the capital and largest city of the Northwest Territories , Canada. It is located on the northern shore of Great Slave Lake, approximately south of the Arctic Circle, on the west side of Yellowknife Bay near the outlet of the Yellowknife River...	January 1991	62°28′51.2"N 114°28′50.4"W

External links

• CDGPS
• CDGPS (Canada-Wide DGPS Correction Service)
• GPS·C Distribution Using NTRIP — PDF format