Page 18 - Volumer 13 Number 7

New Satellite-based
ADS-B Receivers –
A Boost for ATC and Safety
by Rob Mark
In early January, the eighth and final SpaceX Falcon 9 rocket lifted off from Vandenburg AFB in California on a mission for Iridium Communications. Seven of those eight rockets carried 10 Iridium NEXT satellites with the final carrying just five, 66 in all. Each satellite placed itself into a low-earth orbit replacing Iridium’s original satellite-phone constellation launched by Motorola in the 1990s. The new Iridium network will improve satellite phone service, but it will also profoundly improve air traffic control and aviation safety around the world, as each new satellite also carries an ADS-B receiver.
Now if you’re thinking a satellite- born ADS-B receiver is simply redundant to the thousands of ground- based receivers that already exist, you’d be right ... almost. Those of us flatlanders who fly IFR in the United States almost never hear ATC utter the phrase “Radar contact lost,” because coverage is just short of awesome around big cities and at least a few thousand feet in the air while en route.
Fly out west though, or up in Alaska, or away from the Atlantic, Pacific or Gulf shores and that phrase is probably more familiar. That’s because the radar technology that bounces a radio signal off an airplane making it visible to air traffic controllers, a system first deployed during World War II, works by line of sight, just like VHF radios. That means aircraft operating in mountainous regions, over open water or jungle can’t always be seen. Aircraft flying near heavy precipitation can also become nearly invisible to ATC on standard radar.
When aircraft fly outside of ground- based radar contact, ATC must
16 • KING AIR MAGAZINE
JULY 2019