Air navigation service providers (ANSPs) have extended their ability to track aircraft flying on far northern Atlantic routes by installing automatic dependent surveillance-broadcast (ADS-B) stations in Greenland, the Faroe Islands and Iceland.

This year Saab Sensis announced a contract with Danish ANSP Naviair to install five ADS-B stations in Greenland and two in the Faroe Islands, an island group within Denmark’s jurisdiction. In 2011, Iceland’s ANSP Isavia chose German provider Comsoft to supply eight ADS-B stations in that country. The project was originally intended as a joint procurement, but Naviair and Isavia ultimately decided to make separate contract awards.

Through ADS-B, aircraft transmit their position to the ground and to other nearby aircraft on the 1090 MHz “extended squitter” frequency about once per second. The ground station networks in Iceland, Greenland and the Faroe Islands will feed aircraft position reports to Iceland’s Reykjavik area control center, providing a far northern surveillance corridor for transatlantic traffic between Europe and North America. The Reykjavik ACC manages about 5.4 million square kilometers of airspace in total, ranging from the Greenwich meridian in the east, over to the west of Greenland, and from the North Pole to south of the Faroe Islands, near Scotland. Isavia reports that 107,998 flights transited this control area in 2012. “You’re going to get an arc of coverage on those North Atlantic routes which will be a good thing,” said Marc Viggiano, Saab Sensis president and CEO.

ADS-B coverage supports reduced separation of equipped aircraft and provides improved surveillance for search-and-rescue operations. In addition to oceanic surveillance, ADS-B supports aircraft tracking in harsh, remote regions where radar installations are not feasible because of ice loading and wind problems. The Saab Sensis ADS-B transceivers can also calculate the position of aircraft through multi-lateration of their transponder replies by multiple ground stations, a technique that enables independent verification of ADS-B data and serves as a backup surveillance system. The company estimates that 70 percent of airliners transiting the Reykjavik control area are properly equipped and transmitting ADS-B signals.

While the Naviair program is not a large project in terms of the number of ground stations being installed, it represents a further expansion in the worldwide adoption of ADS-B for aircraft surveillance, Viggiano said. Saab Sensis also provides ground stations for Canadian ANSP Nav Canada, which started ADS-B surveillance over Hudson Bay in 2009 and northeastern Canada in 2010. Nav Canada has also placed four ADS-B ground stations in Greenland to support oceanic surveillance in the North Atlantic airspace managed by the Gander area control center. It activated that system in March 2012, giving Gander controllers the ability to safely reduce aircraft separations and approve more efficient flight profiles.

In 2011, Swedish ANSP Luftfartsverket selected Saab Sensis to deploy a wide area multi-lateration (WAM) system across Sweden to complement and replace that country’s secondary surveillance radar infrastructure with lower maintenance, nonrotating sensors that support a transition to ADS-B surveillance. That same year, Austro Control of Austria chose Saab Sensis to deploy a WAM and ADS-B infrastructure consisting of 62 ground stations.

The company is providing an ADS-B system to Norwegian ANSP Avinor for surveillance of helicopter traffic serving oil and gas platforms in the Norwegian section of the North Sea. It is supplying WAM systems to NATS in the UK for area surveillance around airports including Edinburgh Airport, Scotland’s busiest.