Impact quantification of satellite outages on air navigation continuity

Advanced receiver autonomous integrity monitoring (ARAIM) using multiple global navigation satellite system constellations is expected to bring significant navigation performance improvement to civil aviation. However, using multiple constellations, the higher number of satellite outages due, for example, to routine station keeping manoeuvres, could significantly increase continuity risk. In response, this study proposes a new method to rigorously quantify the impact of satellite outages on navigation safety. To achieve this, integrity and continuity risk bounds are derived, which account for all possible outage conditions. In addition, the proposed approach allows to determine whether an exclusion function is needed following an outage event. The method is implemented to analyse horizontal ARAIM (H-ARAIM) availability performance. Results indicate that dual-constellation H-ARAIM can provide high service availability, where both integrity and continuity requirements are met.