DGPS (Differential Global Positioning Service) is a navigational system using the GPS system of satellites that circle the earth plus ground stations with limited signal range. The combination provides greater accuracy than GPS alone. DGPS requires receivers for both GPS and DGPS signals to achieve greater location accuracy.
DGPS service in Canada is operated by the Canadian Coast Guard. 18 stations have been available for positioning and navigation since 1997 (in test mode). Refer to Radio Aids to Marine Naviation (RAMN) for coverage for each station (see station chart below).
Differential corrections are based on the NAD 83 datum position of the reference station antenna and positions obtained using DGPS should be referenced to this coordinate system only. DGPS receivers must be set to the WGS 84 datum in order to obtain optimum positioning accuracy.
Check the NOTMAR On-line Service, which distributes "Notice to Mariners" (chart updates) and "List of Lights, Buoys and Fog Signals". They also publish planned removal of aids to navigation in time for mariners to comment or make recommendations. Downgrading navigational aids is a direct result of planned reliance of commercial shipping on electronic navigation systems such as DGPS and electronic charts.
DGPS is being used for navigation on the Atlantic and Pacific coasts, most of the St. Lawrence River, Labrador, Georgian Bay, Riviere-du-Loup, and southern Nova Scota. The U.S. GPS system will continue to cover the remainder of the Great Lakes.
Id Nos DGPS
of Station Freq
Station Name Stations ID Lat Long [kHz] Bits/sec
________________ ________ ____ _______ ________ ____ ____
Alert Bay BC 300,301 909 50 35 N 126 55 W 309 200
Amphitrite Pt BC 302,303 908 48 55 N 125 32 W 315 200
Cardinal ON 308,309 919 44 47 N 75 25 W 306 200
St.Jean Richelieu QC 312,313 929 45 19 N 73 18 W 296 200
Lauzon QC 316,317 927 46 48 N 71 09 W 309 200
Partridge Island NB 326,327 939 45 14 N 66 03 W 295 200
Pt. Escuminac NB 332,333 936 47 04 N 64 47 W 319 200
Fox Island NS 336,337 934 45 19 N 61 04 W 307 200
Cape Race NF 338,339 940 46 39 N 53 04 W 315 200
Cape Ray NF 340,341 942 47 34 N 59 09 W 290 200
To receive Notices to Mariners monthly editions, phone the Canadian Coast Guard Marine Navigation Services Directorate at (613)990-3037
