NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Turning Off the GPS
From: Marcel Tschudin
Date: 2006 Apr 5, 10:23 +0300
From: Marcel Tschudin
Date: 2006 Apr 5, 10:23 +0300
Please correct me if I should be wrong: Since GPS is controlled by the US military it only needs a decision from the US administration to swich it off. This is, to my understanding, the reason why Europe decided to set in place their own system called EUREKA.
Marcel
On 4/5/06, Lu Abel <lunav@abelhome.net> wrote:
With all respect, Gordon, it would take a lot more technology than the
terrorists have to turn off GPS much less to make it give incorrect
positions. GPS uses satellites. One would need satellite-killer
missiles to "turn off" GPS. Only two or three countries (USA, Russia,
China?) have the technology (which, BTW, includes the technology and
infrastructure to track and identify the target before saying to the
missile "go get 'em"). To make GPS give the wrong position would
require taking over the US's GPS control centers and I'm sure the US
military has put a lot of thought and effort into preventing that.
There are GPS jammers available on the arms market, but they work only
over a small theater of operations. Nowhere I'd be sailing, hope you
won't be there either.
Last but not least, terrorists are interested in, well, terror. I
suspect they'd far rather kill a few thousand of their perceived enemies
than inconvenience them by turning off GPS....
Lu Abel
Gordon Talge wrote:
> Just for the heck of it, I wonder what would happen,
> if some terrorists managed to turn off the GPS system, or
> maybe even better, have it give the wrong positions.
>
> I have noticed that a lot of people seem to say they keep
> a sextant and tables, etc, for backup. The problem that I
> see with that is it takes a lot of practice to get good at using a
> sextant and working out sights by hand. Someone who has
> only tried out their sextant on a calm day or on the beach,
> may find it hard to get a decent shot on a pitching boat
> or ship, and then work out a sight where one slip of a
> plus or minus, or wrong column, would make it all for naught.
>
> BTW,
>
> Has anyone seen those German films of the U-Boats during World War II
> in the North Atlantic pitching and rolling? I start getting seasick
> just watching it. I saw one where a German Officer was taking a noon
> sight on a sub like that. They may have been the enemy, but they
> sure had guts. (It took guts to stand up to them too)
>
> -- Gordon
>
>