Enhanced APNT in Critical Terminal Areas

This paper presents a methodology for selecting airports to be equipped with enhanced Alternative Position Navigation and Timing (APNT), so as to best respond to a contingency in which the airspace needs to be vacated quickly in the absence of satellite navigation services. For the performance evaluation we propose a scenario, which constrains the search for an optimal solution. We discuss the implications of the findings and propose a priority list of airports to equip with enhanced APNT services.