Sensis Multistatic Dependent Surveillance to Support Airport Growth at London Heathrow Airport

DEWITT, NY - April 25, 2005 - Sensis Corporation today announced that National Air Traffic Services, Ltd. (NATS) has awarded a contract to expand Sensis Multistatic Dependent Surveillance (MDS) at London Heathrow Airport. The expanded multilateration system will provide improved surface surveillance for the area surrounding the new Air Traffic Control (ATC) tower scheduled to open in 2006. At London Heathrow Airport, MDS provides surveillance in the runway, taxiway and gate areas to ensure safe, efficient movement of aircraft and airport vehicles.

In November 2002, London Heathrow Airport became the world's first airport operational with multilateration using Sensis MDS. To address the airport expansion, NATS is augmenting its Sensis MDS for surveillance of the airport surface. As a part of the expansion, Sensis is also providing a new MDS central processor to be installed in the new ATCT that will include a test system to validate system performance without the need to take the system out of service. Such testing is necessary, for example, when the layout of the sensors has changed; there is an increase in surveillance coverage; or the system is augmented to address architecture changes at the airport.

"Sensis MDS provides an important part of the ATC infrastructure at Heathrow," said Graeme Henderson, Manager of Surveillance and Display Systems for NATS Airports. "MDS assisted air traffic controllers in handling 476,000 movements in 2004 - an increase of 2.6 percent."

Sensis MDS, a transponder multilateration system, uses low-cost, non-rotating sensors to detect and track the movement of aircraft or vehicles based on their transponder signals. With precision comparable to global positioning systems, a higher update rate than traditional airport surveillance radar, and consistent surveillance performance regardless of weather conditions, MDS provides significant benefits.

"The upgrade at London Heathrow demonstrates the adaptability of MDS to meet the changing needs of our customers," Marc Viggiano, Sensis Air Traffic Systems Division president. "Many airports are expanding their terminals, adding aircraft stands, runways or building new towers in order to meet capacity demands. Having a flexible surveillance system is essential to accommodate such growth in a cost effective, safe manner."

In addition to being operational at London Heathrow Airport, Sensis' multilateration technology is also operational for ground surveillance at Charles de Gaulle Airport, Geneva International Airport, Vienna Airport and Zurich Airport. MDS is being installed at three additional European airports - Amsterdam Airport Schiphol, Brussels Airport and Frankfurt Airport. For enhanced terminal surveillance, Sensis' multilateration technology is operational at Innsbruck Airport and being deployed at Frankfurt Airport. Further, the U.S. Federal Aviation Administration is deploying Sensis' multilateration system to 34 airports as part of the Airport Surface Detection Equipment, Model X program (ASDE-X).