[SC Swamp Fox]

That test area is centered on an area the US Navy uses very regularly for operational testing. They may want to see how ships, aircraft and systems function when GPS is not available.

[backwoods-engineer]

That test area is centered on an area the US Navy uses very regularly for operational testing. They may want to see how ships, aircraft and systems function when GPS is not available.

That must be very inconvenient for Georgians & South Carolinians. I am all for troop preparedness, but GPS has become an important civil navigation tool. They can simulate radar outage; why not simulate GPS outage?

[r9etb]

For those in the know, the Coast Guard maintains a handy site for things like this.

Their Local Notice to Mariners link states:

GPS SIGNAL TESTING
DUE TO TESTING ON GPS FREQUENCIES USED IN SHIPBOARD NAVIGATION AND HANDHELD SYSTEMS. GPS SYSTEMS THAT RELY ON GPS, SUCH AS E-911, AIS AND DSC, MAY BE AFFECTED WITHIN A 150 NM RADIUS OF POSITION 30 49.09N 80 28.18W. DURING THIS PERIOD GPS USERS ARE ENCOURAGED TO REPORT ANY GPS SERVICE OUTAGES THAT THEY MAY EXPERIENCE DURING THIS TESTING VIA THE NAVIGATION INFORMATION SERVICE (NIS) BY CALLING (703) 313-5900 OR BY USING THE NAVCEN WEB SITE'S GPS REPORT A PROBLEM WORKSHEET AT WWW.NAVCEN.USCG.GOV.

[Richard from IL]

There’s a much easier way to do this. See how they navigate without GPS! My Dad helped invent GPS in the 60s and 70s. His system was called TIMATION for TIMe navigATION.