Reliability and availability of GPS measures in airport landing systems

In the last decades, the modern airports have considerably increased the traffic to manage. Consequently, the requirement of technological solutions in order to control vehicles and airplanes in relevancy areas (such as parking area, taxiways and runways) is increased. Among various considered solutions, the more efficient ones use Global Positioning System receivers to establish location of moving objects into the airport. Thanks to this solution, it is possible to increase both the efficiency in runway usage and the safety in ground movements. Nevertheless navigational systems like Galileo or GLONASS cannot be considered as "high availability systems". For examples, positioning service can be interrupted by unintentional radiofrequency interferences, or terrorist attacks through techniques known as "antenna jamming" and "code contamination". In this paper, these problems are analyzed in the context of airplane ground control, and a secure system is suggested. Especially, technical solutions are adopted in navigational routines using Global Positioning System receivers, in order to improve reliability and security, and above all to guarantee a narrow range of variation for positioning for the whole necessary time.