The U.S. Air Force’s first GPS 2F satellite has begun broadcasting its new civilian L5 safety-of-life signal, to be used for air-traffic control and other functions, according to a June 10 Air Force press release.
The Air Force launched the GPS 2F-1 satellite May 27 into a circular orbit 17,600 kilometers above the Earth. It is the first of 12 GPS 2F satellites that will launch over the next several years before the service moves on to launching the GPS 3 satellites in 2014.
Test transmissions of the satellite’s two other civil signals, L1 and L2, which are both transmitted by previous generations of GPS craft, began June 5, the press release said. The L5 signal will be turned on intermittently during the satellite’s three-month check-out phase for various tests, it said. All future GPS satellites will broadcast the L5 signal for use by civil aviation and search-and-rescue authorities.