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Air Traffic Surveillance — Building Capacity and Enhancing Safety

Surveillance of aircraft is a key requirement of any effective air traffic control system. Classical methods of surveillance, both ground-to-air and air-to-air, have their limitations depending upon the environment in which they are used. These limitations primarily manifest themselves in terms of cost and capacity, with surveillance capability already being a limiting factor in the growth of air traffic in certain regions. Various methods and applications are being developed to overcome surveillance limitations on air traffic growth, the primary objective of which is to enable increased traffic flows whilst enhancing the existing levels of safety. Developments underway in various regions of the world are considering both near-term and longer-term enhancements to surveillance capability as part of a more effective air traffic management system. One prime focus of these developments is a shift away from classical ‘active’ surveillance to a ‘passive’ surveillance based system where the aircraft is responsible for providing the necessary surveillance data rather than the interrogating system. Such an approach can provide significant enhancements in terms of cost and capacity but also brings potential safety risks that need to be effectively managed, particularly during the transition. The objective of this paper is to outline the benefits that such a transition could provide whilst highlighting some of the key safety issues and how they could be addressed. The paper concludes with a vision of a future air traffic surveillance system and a safe transition towards it.