Much positive news about the future of civil air navigation broke late last year. Russia and Europe signed agreements to secure the future of their respective satnav systems, Russia’s GPS-like global navigation satellite system (Glonass) and Europe’s Galileo; the White House Office of Science and Technology published a U.S.
Released last month, the 2005 Federal Radionavigation Plan (FRP)–a joint production of the DOT, DOD and the Department of Homeland Security–provides a useful guide to what air navigation will be like between now and 2020. Of course, federal crystal balls occasionally can be cloudy, especially when they peer 14 years into the future.
In 1997 the President’s Commission on Critical Infrastructure Protection, which was charged with examining threats to our national security, recommended an assessment be made of the vulnerability of the U.S. transportation infrastructure if it had to rely on GPS.
As part of its evaluation of loran as a potential backup to GPS, the FAA has contracted Rock-well Collins to build a combined GPS/loran variant of its standard multimode navigation and landing receiver. The unit’s primary function will be to provide GPS navigation, with automatic switchover to loran should GPS signals be lost or degraded, and automatic reversion to GPS when normal service resumes.
A study commissioned by the NGATS Institute on behalf of the FAA’s JPDO and prepared by the advanced engineering and sciences division of ITT determined that eLoran (for enhanced) has “the highest overall preference rating…particularly in the U.S.” as a backup for satnav receivers in the event of failure or interference.
A satellite navigation backup study commissioned by the JPDO has given eLoran “the highest overall preference rating...particularly in the U.S.” Not yet publicly released, the 180-page document was prepared by ITT’s advanced engineering and sciences division and assessed seven candidates against a series of essential requirements. The candidates include DME/DME/INS; GNSS/INS; eLoran; VOR; “hardened” GNSS; terrain mapping; and multilateration.
Occasionally, GPS satellites are spread across the sky in configurations that prevent a receiver from calculating a good position fix. When that happens, the unit’s receiver autonomous integrity monitor (RAIM) will generate an alert to the pilot to use an alternative navigation source.
AIN was informed that the Departments of Transportation and Homeland Security were expected to announce jointly late last month that the U.S. loran transmitter network will continue in operation. How long the system will remain in service is uncertain, but observers believe it could be 10 years, and possibly longer. An independent panel of experts– chaired by “father of GPS” Dr.
Although the decision has not yet been officially announced, AIN has learned the Departments of Transportation and Homeland Security have agreed that loran should continue operating for the foreseeable future. Key influences were the unanimous endorsement by an independent panel of experts convened by the agencies, plus the overwhelming positive response to an earlier public survey regarding the system’s continuance.
Comments are due tomorrow on a request for public input to help federal agencies decide if there is a need to continue to operate or invest in the loran-C radio navigation system beyond FY 2007 (which ends September 30). While the current loran-C system is based on technology developed in the 1960s, some of the stations have been updated to allow for an enhanced signal (eLoran).