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Re: [PSUBS-MAILIST] Re: UW-DGPS
Yes, selective availability was turned off during the Gulf war. The reason
was that families were sending civilian handheld units over there to the
troops. Even though they were 100 meters off their mark, a GI could still
tell what side of the line he was on. With all the desert and no
geographical landmarks and sometimes no roads, a handheld GPS unit was as
coveted as nylons were in WW2. Differential correction can be generated by a
number of devices. A company called Differential Corrections makes a
receiver that connects to the GPS unit. It is broadcast from a local radio
station that broadcasts the signal as a subcarrier. You have to contract
with this company. They have contracts with radio stations all over the
country. Another way to correct the signal is via a coast guard beacon.
There is one just outside of St. Louis Mo, on either the Mississippi River
or the Missouri river, and the signal can be received all the way out in
Columbia Mo (110 miles). Unfortunately we had to contract with the DC
company since we have a lot of valleys and the CG signal was too weak. The
FM signal however, was adequate in these locations.
Just a little info for you guys. The way to go is with the CG, as the signal
is free (tax dollars, please don't get off the subject on this one). All you
need is a receiver, and as long as you're within range, you can get accuracy
down to a few meters.
Yes, the Ruskies have their own GPS. Our concern though is with the rogue
nations (please lets not get off the subject on this one either :) ). I
believe that eventually the DOD will drop the SA, however, i've been told
that they don't want to do this because it will be admitting that there is a
civilian dependence on their equipment and they will then have to answer to
the public for it's use, modification, application. Right now they like
being in the position of responding to any complaints or requestsby saying
that the system is strictly for military purposes, and that any other use is
a privilege... I'm not sure how valid the last reason is, but I've heard it
from some military types....Suds
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