Using Multiple Reference Station GPS Networks for Aircraft Precision Approach and Airport Surface Navigation

Ahmed El-Mowafy

Department of Civil and Environmental Engineering, UAE University, P.O.Box 17555, Al Ain, UAE.

DOI:                 

Abstract

The use of multiple real-time reference stations (RTK Networks) for positioning during the aircraft’s precision approach and airport surface navigation is investigated. These existing networks can replace the proposed airport LAAS systems and have the advantage of improving coverage area. Real-time testing of the proposed technique was carried out in Dubai, UAE, with a helicopter and a small fixed-wing aircraft using a network known as the Dubai Virtual Reference System (DVRS). Results proved the feasibility of the proposed approach as they showed that cm to sub-meter positioning accuracy was achieved most of the time. For some periods, only meter-level positioning accuracy was available due to temporary breaks in reception of the network carrier-phase corrections. Some solutions to improve availability of the corrections are discussed. It is also proposed to integrate the GPS with an IMU. The inertial system aids positioning during periods when the corrections are lost, as well as providing attitude information. The GPS and IMU systems were integrated using a decentralized adaptive Kalman filtering technique. The measurement noise covariance matrix and the system noise matrix are adaptively estimated, taking the aircraft dynamics changes into account. Tests of the integrated system show that it has a good overall performance, and navigation at categories III and II can be achieved during short outages of RTK-GPS network corrections.

Keywords

Global Positioning, Airborne Navigation, Wide Area Networks, Adoptive Systems, INS

Conflicts of Interest

The authors declare no conflicts of interest.

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