report of the action team on global navigation satellite systems (gnss)

an air navigation service dedicated to <strong>the</strong> safe movement <strong>of</strong> air traffic throughout <strong>the</strong> country andthrough oceanic airspace assigned to Canada under international agreements. The company’sinfrastructure consists <strong>of</strong> seven Area Control Centres, one stand-alone terminal control unit, 78flight service stations, 42 control towers, 41 radar sites and approximately 1,400 ground-basednavigational aids across Canada.199. For <strong>the</strong> aviation community, GPS signals meet accuracy requirements for en-routethrough non-precision approach. GPS by itself does not meet integrity or accuracy requirementsfor aircraft precision approach operations. NAV CANADA has commissioned over 250 GPSstand-alone approaches providing increased airport usability in many cases.200. Recent developments in <strong>the</strong> United States Wide Area Augmentation System (WAAS)program suggest that it may be possible to obtain service from WAAS in sou<strong>the</strong>rn Canada. NAVCANADA is exploring this possibility. The only viable way to obtain full WAAS service inCanada, however, is to field a network <strong>of</strong> reference stations linked to FAA master stations in <strong>the</strong>United States; this network would be called <strong>the</strong> Canadian WAAS, or CWAAS. NAV CANADAand <strong>the</strong> FAA have been planning accordingly since <strong>the</strong> mid 1990s. No decision has been made t<strong>of</strong>und CWAAS; such a decision depends on factors related to <strong>the</strong> ability <strong>of</strong> CWAAS to deliverlevels <strong>of</strong> service that would bring benefits to aircraft operating in Canada.201. NAV CANADA is also investigating <strong>the</strong> use <strong>of</strong> <strong>the</strong> Local Area Augmentation System(LAAS) installations in Canada as this technology develops.[Reference: NAV CANADA Satnav Transition Strategy May 2002http://www.navcanada.ca/contentEN/serviceprojects/satnav/See also http://www.navcanada.ca/contentEN/news/corpDocs/techWatch/default.asp for NAVCANADA updates and http://www.tc.gc.ca/tdc/projects/air/b/9855.htm for information aboutGPS advanced aviation navigation program at Transport Canada.]University <strong>of</strong> Calgary’s regional differential RTK test network202. The University <strong>of</strong> Calgary is deploying a test network that will initially consist <strong>of</strong> 16stations spaced at 40 to 70 km to study multiple reference station DGPS RTK and real-time watervapour estimation on a regional basis.Canadian commercial GPS differential services203. There are some Canadian companies <strong>of</strong>fering GPS augmentation services coveringvarious parts <strong>of</strong> Canada. This is done from wide coverage by broadcasting corrections via acommunication satellite to local services broadcasting via radio frequencies from a single basestation. The services also range from low accuracy single frequency pseudorange corrections tolocal, high accuracy, dual frequency RTK type services. Most major cities in Canada have somesort <strong>of</strong> commercial GPS augmentation service.37