Integrated Inertial Navigation System with multiple APNT ranges: Expected performance and considerations

Inertial sensors constitute an essential part in civil avionics systems. It has also been identified as a required system to meet the foreseen availability requirements in the context of Alternative Position Navigation and Timing (APNT). For example, DME/DME/Inertial (DDI) is currently considered for RNAV 1.0 operations. In this work, we look beyond DDI and investigate the possibility of an integrated inertial system with multiple APNT ranges. Thanks to our simulation framework, we evaluate in different scenarios the integration of inertial system with ranging sources using real DME locations. Based on the results, we finally analyze and comment on the limitations, implications and issues of using tactical grade instead of navigation grade inertial sensors.