Technical Overview

Space-based Automatic Dependent Surveillance-Broadcast (ADS-B) will provide unparalleled 100 percent global surveillance coverage to receive and process ADS-B signals broadcast from aircraft equipped with 1090 MHz ADS-B transponders, which operate on the same frequency as traditional Mode A/C/S transponders, including DO-260, DO-260A and DO-260B (Link Versions 0, 1 and 2, respectively), as well as DO-260B/ED-102A, the current standard.

The Aireon System and Iridium NEXT
Iridium NEXT is hosting the Aireon system and is the only satellite constellation with the capability and reach to enable global air traffic surveillance due to its orbital configuration. This configuration provides complete global coverage, including oceanic and polar regions, without the need for ground stations. No other system, existing or planned, will enable such an opportunity for aviation stakeholders.

System Overview
ADS-B information broadcast from the aircraft will be received by the Harris-built Hosted Payload (AHP), which transfers aircraft data from satellite to satellite down to Aireon’s ground-based Teleport Network (TPN) and Aireon Processing and Distribution (APD) system. With the assistance of partner, Harris, the APD decodes and verifies the data, and delivers the data to the appropriate stakeholder facilities that have subscribed to the Aireon service.

Aireon Technical Graphic

The Data
Aireon’s surveillance infrastructure will provide ANSPs with information derived from an aircraft’s onboard equipment, sensors and ADS-B transponder, including horizontal position, altitude, velocity, aircraft identification and call sign. This data is often combined by the ANSP with ground-based surveillance and flight plan information for integration with ATC systems to provide a single representation of a given aircraft.

The Antenna
In order to ensure reliable satellite reception, an A1 class transmitter and top mount aircraft antenna (commonly found on most commercial aircraft and private jets), is required due to the space-based nature of Aireon’s receivers. Aircraft with a Traffic Alert and Collision Avoidance System (TCAS) to help prevent midair collisions are typically equipped with both top and bottom mount antennas.

Position Updates
Unlike traditional en-route radars, which rotate once every 12 seconds, Aireon’s space-based satellites can provide position updates up to twice per second, with an expected Update Interval (UI) performance of eight seconds, which would meet the five nautical mile (5 NM) application needs of en-route separation services, according to EUROCAE ED-129B and Eurocontrol GEN SUR specifications.

Surveillance Datalink1090ES ADS-B (DO-260 versions 0, 1, 2)
Aircraft Transmitter Classes SupportedA1 or higher with a top-mount antenna
Data Format to ANSPASTERIX CAT021, CAT023, CAT025, CAT238 and FAA CAT033 and CAT023
System CoverageContinuously Global
Availability≥ 99.9%
Latency≤ 1.5s to a ATC Surveillance Tracker
Update Interval95% of reports ≤ 8s over most areas