26 December 2017
Real-time satellite tracking of commercial aircraft anywhere on the globe promises to become a systematic reality in 2018, as three companies prepare to supplement traditional ground-based air traffic monitoring systems with collection from orbit of airliners’ ADS-B positioning signals.
Aerial & Maritime (A&M), based in Denmark, expects to offer its service from the second quarter, while Aireon (Virginia) and Spire (San Francisco) are promising to have operational aircraft tracking services running before November, when by international agreement airlines will be required to acquire position data on all flights at least every 15 minutes.
Aircraft have gone missing as long as there has been aviation, but the push to develop means to locate aircraft anywhere on their routes began in earnest with the March 2014 disappearance of Malaysia Airlines flight MH370; the Boeing 777, carrying 239 passengers and crew, deviated from its Kuala Lumpur-Beijing flightplan, ceased communication, and was untrackable once out of sight of ground-based radar. The aircraft is presumed to have flown until its fuel was exhausted, but extensive search of probable crash zones across vast tracts of the Indian Ocean have turned up no clues.
The scale of the problem is well-illustrated by two figures. According to one UN agency, the International Telecommunication Union, at any given time there are 59,000 aircraft in flight worldwide. As Aireon notes, 70% of the world’s so-called “Flight Information Regions” are not covered by any real-time surveillance – that is, they are out of sight of radar or ground-based ADS-B receivers. Hence the attraction of satellite tracking.
After MH370, the International Civil Aviation Organisation (ICAO), the UN agency tasked with governing air transport, agreed a series of protocols for tracking aircraft and, in the event of a crash or ditching, initiating search and rescue. One highlight of this Global Aeronautical Distress and Safety System (GADSS) is the requirement, from November 2018, that airlines obtain – every 15mins – a four-dimensional position report for all aircraft seating more than 19 people.
The plan got a notable boost with the 19 December adoption by the ITU of main technical principals of enhanced aircraft ADS-B – Automatic Dependent Surveillance-Broadcast – via satellite. The ITU sums up the technology thus: “The technique is termed ‘automatic’ because there is no intervention from the pilot or interrogation from terrestrial stations, and ‘dependent’ because the data is dependent upon on-board systems such as global positioning system and altimeter.” ADS-B via satellite, says the ITU, “would enhance surveillance of aircraft, particularly in areas where terrestrial receivers cannot practically be deployed, such as in oceanic, trans-polar and remote regions”.
With the world’s airliner fleet either already equipped with ADS-B equipment or being upgraded by November 2018, the missing link is the satellite transceiver. An experiment by the European Space Agency and Germany’s DLR aerospace agency had determined by mid-2015 that “detection of aircraft can work from space with no showstoppers, despite the fact that these signals were never designed to be picked up from so far away.” DLR’s Toni Delovski, who was overseeing the experiment, noted at the time that “the signals are beamed sideways from their host aircraft rather than omnidirectionally, making them harder to detect from orbit.”
ESA and DLR were picking up aircraft signals with a single ADS-B payload added to a small satellite – about 1m cubed – called Proba-V, whose main task is to measure vegetation. But between launch in May 2013 and May 2015, that single receiver had picked up 25 million positions from more than 15,000 separate aircraft.
A&M, Aireon and Spire are taking different approaches to the problem. A&M’s service relies on nanosatellites being built by sister company GomSpace; it already offers “real-time/near real-time monitoring” of automatic identification system (AIS) signals from commercial vessels between 37N and 37S latitude. Spire takes a similar tack; describing itself as a “satellite-powered” data and analytics company, it has orbited some 50 cubesats over the past four years, and in 2018 expects to add an ADS-B aircraft tracking service to its ship tracking and weather products.
Aireon is flying hosted payloads aboard an eventual 66 Iridium NEXT low-Earth orbit communications satellites, including 10 orbited on 22 December by a SpaceX Falcon 9 flight from Vandenberg air force base in California – a launch which took Iridium’s deployment campaign to its halfway point. The Iridium spacecraft are also hosting AIS payloads for ExactEarth; both hosted payloads were built by Harris.
Spire highlights the obvious appeal of satellite monitoring – its business is to deliver “insights into the parts of the world where collecting data is notoriously difficult”. As with aircraft and ADS-B, ships broadcasting AIS signals can be tracked by ground stations and, increasingly, by satellite, to supplement the principal system of radar. Spire says its maritime service is improving with “new satellites entering orbit nearly every month”, and receiving “continuous” on-orbit software updates. One recent new customer is Global Fishing Watch, which is using Spire maritime tracking data to monitor illegal and overfishing.
As the use of Spire data to combat illegal fishing suggests, the application of these services goes beyond the primary safety function of tracking vessels and aircraft. A&M’s maritime service, it says, helps ship owners, traders, shipbrokers, logistics companies and “many other customers” keep track of vessels. For aircraft, it says, national airspace and other authorities can use ADS-B data to “assist with seamless billing of overflight charges”.
But commercial use of flight data – identifying specific aircraft – goes potentially much further. Aireon will offer services based on analysis of its repository of ADS-B data, for customers wanting to understand “aviation trends and performance”. As the company notes, current aircraft movements data suffers from being “stitched together” from various sources and so “do not offer a complete or single picture and often have significant gaps in fleet data, regional limitations… and incomplete data across major air traffic routes”. Adds Aireon: “Most airspace analysis is done with less-than-accurate assumptions and relies on scheduled information and flight plans, rather than actual routes and diversions, which often differ from the original plan when the realities of traffic congestion and weather events intercede” – a shortcoming it promises to start relieving in 2018.