Aireon space based ADS-B performance model

Abstract

Global, continuous, low-latency, and high performance surveillance of aircraft via Space-Based ADS-B (Automatic Dependent Surveillance Broadcast) is an emerging technology for the aviation industry. The Iridium-NEXT Low Earth Orbit (LEO) satellites, which will host the Aireon ADS-B receiver payloads, will begin launching in 2015 with all 66 operational satellites in their mission orbit by 2017, gradually replacing the current Iridium satellite constellation and enabling the global ADS-B surveillance services of Aireon [1-3]. Prior to launch, a series of system and receiver models, simulations, and studies were produced in order to estimate metrics of this unique surveillance system such as the expected ADS-B aircraft position update interval. To assess whether the required update intervals for providing aircraft separation services will be achievable, the density of aircraft and other 1090 MHz in-band transmitters must be taken into account with respect to the large satellite beam footprints as a function of time and space (particularly near coastal areas where air traffic is most dense). This work describes a model for calculating the expected impact of aircraft density, mixed avionics equipage, and satellite motion on the ADS-B update interval performance for wide area space-based receiver systems. Additionally, several examples of expected performance based on the model are characterized in various Flight Information Regions (FIRs).