The Wall Street Journal
By ANDY PASZTOR
Dec. 22, 2016 12:52 p.m. ET
Aviation authorities are moving to improve the accuracy and reliability of satellite navigation by enabling aircraft in the future to simultaneously rely on separate orbiting systems run by the U.S. and Europe.
Such proposed changes, recently endorsed by the U.S. Federal Aviation Administration’s top outside technical advisers, set the stage for major changes in how pilots will use space systems for precise position data and flight routes. The upshot would be safer skies due to more exact information about locations of planes and reduced likelihood of gaps or hacking of signals by making more satellites available to users.
For the first time, formal plans envision airliners, business jets and even some private planes processing signals at the same time from both Global Positioning System satellites operated by the U.S. Air Force and Europe’s still-unfinished Galileo constellation.
By taking preliminary steps to develop joint standards, U.S. and European experts are moving toward installation of common equipment over roughly the next decade on both sides of the Atlantic. They say the move provides added protection against satellite malfunctions, hostile jamming and other potential hazards that could disrupt ubiquitous, space-based navigation signals that are essential to the aviation industry.
“It is a big deal, and we’re trying to move quickly” to establish a joint schedule for setting technical standards for interoperable aircraft receivers, according to consultant George Ligler, one of the U.S. technical experts leading the effort. “It would make the entire global navigation satellite system more robust,” he said in an interview following a meeting of the FAA advisory group’s top policy committee in Washington last week.
Ultimately, some experts predict the strategy could help strapped government budgets by reducing the need for GPS and Galileo—currently operating more than half of its proposed fleet—to launch spare satellites into orbit or take other steps to assure signal redundancy. In effect, the aim is to have each satellite system serve as a backup for the other. “Pretty much everybody would like to have it,” Mr. Ligler said, adding that it could take until 2025 or 2027 until standards are adopted and common receivers are manufactured and installed on large numbers of airliners. Some industry officials have advocated a faster phase-in of such equipment.
Currently, there is no production of technology certified for routine aircraft use that is able to receive signals from both constellations at the same time.
In a statement, the European Global Satellite Navigation Systems Agency, which runs the civilian-controlled Galileo constellation, said it and the European Union have committed to work with the U.S. to develop prototype receivers intended to rely on multiple constellations.
After more than 15 years of development and various setbacks, 18 of Galileo’s proposed 30 satellites are now in orbit. Newer than the GPS fleet, the system aims to provide more precise location information for aviation and many other users.
The current discussions with the U.S. don’t entail common emergency search and rescue signals.
Progress on satellite-based navigation upgrades could be blocked by engineering challenges or continued delays by the two sides swapping detailed technical specifications. The timetable approved by the U.S. panel calls for final approval of minimum operation standards by 2022, but work schedules and progress benchmarks still have to be coordinated with European counterparts.
Industry experts have predicted it could take half a dozen years for widespread adoption of the anticipated receivers. The FAA and European safety officials would have to take action to make that happen.
U.S. aviation officials have considered negotiating similar agreements with China and Russia, each of which have their own satellite systems for airborne navigation. But American experts have complained that those governments balked at divulging technical data needed to pursue common arrangements.
“It’s fair to say we have almost no data on the Chinese system,” Mr. Ligler said. And for Russia’s evolving satellite constellation called GLONASS, which is switching to new frequencies, he said, “we don’t have the details of what the new signal structure will be.”
Satellite navigation systems are sources of national pride and military capability, with certain operational variables considered classified.
The GPS consists of 31 satellites able to transmit radio signals from specially-designed orbits more than 12,000 miles above the earth. Every user is guaranteed to have access to signals from at least four satellites at any instant.
Despite updates and revised designs intended to protect the constellation from interference, experts continue to worry about jamming and what is called “spoofing” of GPS signals, when phony messages are sent potentially confusing users.
While proposed U.S.-European standards are being developed, other global satellite systems such as Aireon LLC are slated to be deployed to expand real-time surveillance. Backed by a number of air-traffic control providers from Canada and Europe, Aireon will use 66 low-earth orbit satellites to allow controllers to reduce separation between aircraft and help airlines more effectively avoid bad weather.
—Robert Wall contributed to this article.
Original article can be found here: http://www.wsj.com