Electronic graffiti points the way

A method of hanging mobile radio messages in the air like floating electronic signposts may soon be used to help pilots navigate around airports on the ground.

Siemens and Deutsche Flugsicherung have successfully tried out the solution at HanoverAirport. It is designed to simplify navigation for pilots while they are on the ground and make monitoring easier for staff in the control tower.

To find their designated parking position, an air crew currently has to fall back on signs, ground lighting, site plans, radar or instructions from the control tower. But radar is not easily able to pinpoint their exact position, radio traffic is often overloaded, and darkness or fog, unclear taxiway markings or even just the sheer size of the airport make if difficult to find a route.

“Digital Graffiti” from Siemens Business Services and Siemens Corporate Technology offers a potential solution. With this approach, Siemens stores mobile radio messages at particular locations for specific receivers, literally suspending them in mid-air. The message is not passed on to the designated recipient until they have reached the agreed location.

When approaching or moving along the landing strip, the plane picks up a constantly updated plan of the airfield. This shows the planned parking position and the correspondingly marked taxiway, including all sites for construction work and any areas that are blocked off. A digital route is displayed on a screen in the cockpit, and the crew simply has to follow it. This system naturally also works in reverse, from the parking position to the runway.

In certain cases, the system can be more precise than conventional ground radar, as the GPS receiver on the plane reports its position to the tower once every second. As a result, the tower can track the progress of the plane with an error margin of only a few metres.