This past fall, Aireon participated in and sponsored an event called, The International Symposium on Enhanced Solutions for Aircraft and Vehicle Surveillance Applications in Berlin, Germany. The Aireon team shared three papers at this conference which reveal some of the results of the most recent AireonSM system performance tests. We’d like to share these papers containing exciting performance results with you in a three-part blog series. Click here to read the first and second editions.
Aireon’s system testing continues to validate the thoroughness and reliability of the Aireon payloads currently on-orbit. A unique feature of the system is that each Aireon payload has a footprint on the earth’s surface which reflects each payload’s coverage. Adjacent payloads can have overlapping footprints, which creates added reliability, redundancy and safety. But how so?
In the areas where the overlap occurs, the Aireon system picks up two or more measurements of the same information. These measurements can be used to perform Time Difference of Arrival (TDOA) calculations that Aireon has incorporated into a position validation algorithm. This allows for verification of an aircraft’s reported position independent of GPS. What exactly does this mean? It means that the Aireon system is resistant to spoofers, faulty avionics and GPS outages.
How common is the Aireon payload footprint overlap? Almost at all times. Given the size of each Aireon payload’s coverage footprint, all aircraft are covered by at least two satellites at above 43° and below – 43°. Single satellite coverage is most common closer to the equator, but even then, aircraft have an 80 percent chance of being covered by more than one satellite.
Aireon data algorithm testing was performed by using 47 of the satellites in operational orbit. The studies showed that there were over one million TDOA opportunities from 16 million total reports collected in a single hour!
As a company dedicated to safety, with air traffic controllers relying on our data for aircraft separation and more, it’s imperative that we are confident in the data. Incorrect or misleading surveillance information can be extremely hazardous. This is why Aireon has developed this comprehensive method of position validation used to authenticate the integrity of ADS-B data delivered to customers around the world. Aireon is the first surveillance system ever to perform this type of validation via space-based ADS-B.
To view the detailed measured results of the validation algorithm recorded from the Aireon system, read the full paper, “Aireon Independent validation of Aircraft Position Via Space-Based ADS-B”.
This paper is authored by Dr. Michael A. Garcia and John Dolan.