Australian air traffic services provider Airservices Australia has contracted Honeywell to develop a ground-based regional augmentation system (GRAS) to enhance the accuracy and integrity of GPS navigation at Australia’s regional airports, writes Emma Kelly.

GRAS will use a network of VHF radio stations to correct inherent GPS positioning errors. A GRAS reference station compares information transmitted by GPS satellites with the station’s surveyed location. That information is datalinked to VHF transmitters for broadcast to aircraft.

GRAS will improve navigation accuracy, integrity and safety in the en route phase of flight, while in the terminal area it will allow pilots to fly an instrument approach down to within 250ft (75m) above the ground in low visibility or in difficult terrain, says Honeywell.

“GRAS will enable continued operations in inclement weather at many small regional airports that currently do not have instrument approach capability,” says Mike Hoodspith, manager of Honeywell global business development.

Source: Flight International