Attention: TDR Forum Junkies If you have a GPS system, you might want to read this. I got it off of "AVflash" an aviation newsletter in my e-mail at work:
U. S. MILITARY STOPS DEGRADING GLOBAL POSITIONING SYSTEM ACCURACY...
With the "flick of a switch" at the Air Force Space Command this week, your GPS navigation box just got better. As of midnight GMT on Monday, the Department of Defense turned off selective availability (SA), the intentional degradation of the GPS signal that has been supplied to civilian users worldwide. Instead of a 300-foot accuracy, civil GPS users can now expect accuracy to within 100 feet or better. No changes are necessary in anyone's GPS nav boxes to take advantage of the improved signal. Immediate benefits to aviation users include better situational awareness on the ground at airports while taxiing, and more reliable performance from GPS-based terrain avoidance systems while in the approach and landing phase.
... . "SA" TURNED OFF, BUT THEY CAN TURN IT BACK ON FOR THE BAD GUYS...
The discontinuation of SA was made possible by the development of techniques that allow the military to restore the intentional
"dithering" of the timing signal on a regional basis, when required by national security concerns. This would effectively deny the increased GPS accuracy to unfriendly users in that particular area. Arthur Money, assistant secretary of defense, was intentionally vague about how the regional degradation system would work in times of crisis, but did say that if the improved GPS signal were denied to a region such as the Balkans, that users in Athens or Frankfurt would not be affected.
U. S. MILITARY STOPS DEGRADING GLOBAL POSITIONING SYSTEM ACCURACY...
With the "flick of a switch" at the Air Force Space Command this week, your GPS navigation box just got better. As of midnight GMT on Monday, the Department of Defense turned off selective availability (SA), the intentional degradation of the GPS signal that has been supplied to civilian users worldwide. Instead of a 300-foot accuracy, civil GPS users can now expect accuracy to within 100 feet or better. No changes are necessary in anyone's GPS nav boxes to take advantage of the improved signal. Immediate benefits to aviation users include better situational awareness on the ground at airports while taxiing, and more reliable performance from GPS-based terrain avoidance systems while in the approach and landing phase.
... . "SA" TURNED OFF, BUT THEY CAN TURN IT BACK ON FOR THE BAD GUYS...
The discontinuation of SA was made possible by the development of techniques that allow the military to restore the intentional
"dithering" of the timing signal on a regional basis, when required by national security concerns. This would effectively deny the increased GPS accuracy to unfriendly users in that particular area. Arthur Money, assistant secretary of defense, was intentionally vague about how the regional degradation system would work in times of crisis, but did say that if the improved GPS signal were denied to a region such as the Balkans, that users in Athens or Frankfurt would not be affected.
