The DOD’s Navstar GPS reached a new performance level this year, with 30 satellites in orbit versus its minimum required civil complement of 24. Four more satellites add signal coverage and reduce the number of occasional “holes,” or gaps where fix geometry can sometimes fall below navigation standards.
Global Positioning System
The U.S. Air Force last month reiterated its intention to choose a single contractor for a new constellation of global positioning satellites known as GPS III. Teams led by Lockheed Martin and Boeing are competing for the contract to launch eight Block A GPS III satellites by 2013. The Air Force invited bids last month for these first satellites, the foundation for an enhanced system scheduled to start operating in 2018.
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.
Northrop Grumman delivered the first production LN-120G GPS-aided stellar-inertial navigation system to the U.S. Air Force last month, to begin the update of the service’s 31 RC-135 Rivet Joint signals intelligence aircraft.
Boeing’s guided bomb business is moving forward with the conclusion of a successful test program, a new contract and a growing SDB II program. The test program concerned the Integrated GPS Antijam System (IGAS) for the Joint Direct Attack Munition (JDAM).
A solar flare 10 times stronger than anything researchers had previously observed or predicted surprised scientists last December, not only because of its size and strength, but because of the effect it had on GPS receivers and other communications systems. Now scientists are looking at previous data and trying to understand how these flares affect satellite signals, in the hope that they can one day prevent further disruptions.
Much ado about nothing is essentially what the FAA is saying about a story that broke this week regarding the validity of using GPS and FMS units after a supposedly new policy was issued in March.
Phoenix-based Honeywell announced last month it had received TSO approval for phase IV, the latest version of the Primus Epic control display system/retrofit (CDS/R). The phase IV upgrade will allow the CDS/R to display electronic charts and maps, as well as satellite weather. In addition to the electronic charts and weather, Honeywell said the CDS/R offers an 8- by 10-inch full-color screen, GPS, satcom capability, TCAS and EGPWS.
AOPA wrote a letter to the FAA last week saying that if a new policy outlined in Advisory Circular (AC) 90-100A is allowed to remain as it is currently written, more than 25,000 GPS users will not be able to use the unit as a substitute for DME or Rnav procedures.
Lingering technical issues are forcing Garmin to delay plans for upgraded WAAS capability in the company's GNS 430/530 and GPS 400/500 panel-mount avionics, according to a spokesman. Explaining that the upgrades will require "a major software rewrite" in addition to minor hardware changes, the spokesman indicated that the capability is now not expected to be available before next year's third quarter.