Assessing the relation of navigation performance using alternative navigation sources and continental en-route airspace safety

Abstract

Satellite-based positioning and time synchronization are vital functionalities for modern aviation, with costly ground-based systems being more and more phased out and replaced by rationalized backup infrastructure. In this process, special attention is paid to the provision of alternative positioning and timing (APNT) functions in terminal flight phases with distance measuring equipment (DME) representing the current and L-Band Digital Aeronautical Communication System (LDACS) a potential future technical solution. The increasing reliance on satellite-based positioning and timing functions on the one hand increases the vulnerability of the air transport system in general, as those functions might suffer from technical outages or functional limitations caused by third parties. On the other hand, precise navigation capabilities serve as an enabler for further optimization of aircraft operations and airspace usage by enabling higher traffic volumes also in enroute airspaces. This would require a viable APNT function, that can also cover this segment of flight. In our work we establish a correlation between navigation performance provided by DME-based and LDACS-based APNT functions as well as airspace inherent surveillance capabilities and procedures on the one side and a qualitative airspace safety metric on the other side. Thus, we allow for an evaluation of these technologies and their potential to safely enable dense traffic operations in enroute airspace.