New APNT ranging signals as an opportunity for rationalizing ground infrastructure

ICAO Annex 10 - Attachment H provides a guidance for a rationalization of conventional radio navigation aids to support Performance-Based navigation. An optimization of terrestrial navigation infrastructure, which includes a rationalization effort and coordinated evolution, is necessary to maintain a sufficient level of safety and operations in case of GNSS outage. This is an opportunity to introduce new signals with better ranging performance. The hybridization of new systems with legacy DME enables a fully backup navigation system. The hybrid systems make possible to decommission older radio navigation solutions. In this paper we present our assessment tool: marginal benefit. Marginal benefit is the ratio between potential DME to be decommissioned and the number of new signals deployed. The marginal benefit plot can be considered a parameter for air navigation service providers (ANSPs) to have a robust backup navigation infrastructure.