[amsat-bb] SA won't be built into future GPS birds

[Nate Duehr]

Just sharing a news snippet... (source AvWeb)

Nate WY0X

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No More Dumbing Down GPS

The Department of Defense says its next generation of GPS satellites 
won’t come with an on/off switch for civilian users. Because the system 
was originally deployed as a military system, the military wanted the 
ability to degrade the accuracy of the signal or eliminate it entirely 
to prevent it from being used against them. But with GPS in everything 
from cellphones to tracking chips in store merchandise, the DoD long ago 
gave up any hope of keeping it a discretionary asset and effectively 
turned off the "selective ability" function in 2000.

However, beginning with satellites deployed in 2013, even that 
capability won’t be included in the system, something that should calm 
the fears of some that their moving map could suddenly disappear without 
warning. "This action to permanently remove SA eliminates a source of 
uncertainty in GPS performance that has been of concern to civil GPS 
users worldwide for some time," DoD said in a news release. That 
undoubtedly means the military has something even better than GPS to run 
its own systems and it will be interesting to see what trickles down to 
the civilian market.