NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Is Celestial Navigation really a backup to GPS Navigation?
From: Geoffrey Kolbe
Date: 2018 Sep 10, 22:51 -0700
From: Geoffrey Kolbe
Date: 2018 Sep 10, 22:51 -0700
Roger W. Sinnott wrote:
"Another possibility, or even high likelihood, is that in time of war the U.S. military would re-impose “selective availability” -- the intentional degradation of GPS accuracy when accessed by civilians. "
During the first Gulf war in 1991, selective availability was actually turned off..... because so many civilian GPS devices were being used by the military. Given that all smart-phones have a GPS device in them, that situation will not have 'improved'.