A Requirements Based Approach to Future Aeronautical Navigation Systems Based on Global Navigation Satellite Systems

The increasing use of Global Navigation Satellite Systems-GNSS in future Aeronautical Navigation Systems-ANS is a current trend in the aeronautical operation and regulation communities. This trend implies the adoption of elements and interactions of a degree of complexity that is still being discussed around the world. Faced with that, we believe that a requirements based approach is an effective tool to deal with such highly complex and integrated systems. In this work we discuss a requirements based approach to future Aeronautical Navigation Systems based on Global Navigation Satellite Systems. To do that, we first briefly present the concept of Communication, Navigation, Surveillance/Air Traffic Management - CNS/ATM, and the current and potential benefits of the adoption of its paradigms. Then, we discuss the use of a requirements based approach in the application of this concept to develop ANS, taking into account that: 1) often, the GNSS ground and space segments are already available, and the airborne segment is the one to be developed; 2) any system to be developed in this area must be considered as part of a system of systems constituted of the three segments; and 3) other interactions must be taken into account. This approach enable us to: 1) identify some relevant implications and interactions that we may miss in a Component Engineering approach; and 2) define a more effective and complete basis of high level requirements to accomplish the objectives related to safety and performance in Aviation.