Since this is equally important to aircrew and ground teams I'm posting this here.
From 20 January to 22 February the DoD will be conducting tests on the GPS system which will result in unreliable or unavailable signals in the southeastern portion of the US (see the source link for a map). NOTAMS will be issued providing specific information, but all aircrews and ground teams should be aware of the potential for GPS disruption.
Source: http://www.engadget.com/2011/01/20/faa-warns-of-ongoing-gps-issues-in-southeastern-us-due-to-defens/
Edit: Proofreading fail
There was mention at our weekly meeting last night that there were going to be similar issues in central CA, but i didn't catch the whole conversation. This came from an FAA controller.
Here is the link to one of the government sites that post GPS Service Interruption Active Notices: http://www.navcen.uscg.gov/?pageName=gpsServiceInterruptions
And the specific document listing the two noted in this thread:
http://www.navcen.uscg.gov/pdf/gps/gpsnotices/GPS_Interference.pdf
Mike
Ahh, frack. As if GPS signals aren't bad enough where I live...