[6996] in cryptography@c2.net mail archive
Re: GPS no longer encrypted
daemon@ATHENA.MIT.EDU (Derek Atkins)
Wed May 3 13:12:40 2000
To: "Trei, Peter" <ptrei@rsasecurity.com>
Cc: cryptography@c2.net, "'Rich Salz'" <salzr@certco.com>
From: Derek Atkins <warlord@MIT.EDU>
Date: 03 May 2000 11:26:02 -0400
In-Reply-To: "Trei, Peter"'s message of "Wed, 3 May 2000 09:59:30 -0400"
Message-Id: <sjmvh0v7j05.fsf@indiana.mit.edu>
Do you mean 13 feet radius or 13 feet diameter? I was seeing a
vertical error of approximately +/-10 feet (although I'd believe 13 ;)
Horizontally I was seeing approx +/- .0015 minutes in both lattitude
and longitude (which equates out to approximately +/-9 feet).
Considering the inacuracy of my measurements, I would mostly concur
with your observations, except that I'd extend it to a sphere (instead
of a circle) of radius 10'. I can't wait to get up flying again :)
-derek
"Trei, Peter" <ptrei@rsasecurity.com> writes:
> Yes, my little Garmin GPS III+ now reports error circles as low as
> 13 feet (as opposed to about 200 before the change). This is *very*
> nice for people who need that level of precision. Of course, minor
> errors in the map database become glaringly obvious when you
> can tell which lane you're driving in, as opposed to merely which
> road you are on.
>
> Over on sci.geo.satellite-nav they're wetting their pants in joy.
>
> Peter Trei
>
>
> > ----------
> > From: Rich Salz[SMTP:salzr@certco.com]
> > Sent: Tuesday, May 02, 2000 10:12 AM
> > To: cryptography@c2.net
> > Subject: GPS no longer encrypted
> >
> > A handful of press releases, including
> >
> > http://www.whitehouse.gov/library/ThisWeek.cgi?type=p&date=1&briefing=0
> >
> > Which starts...
> > Today, I am pleased to announce that the United States will stop the
> > intentional degradation of the Global Positioning System (GPS) signals
> > available to the public beginning at midnight tonight. We call this
> > degradation feature Selective Availability (SA). This will mean that
> > civilian users of GPS will be able to pinpoint locations up to ten
> > times
> > more accurately than they do now. GPS is a dual-use, satellite-based
> > system that provides accurate location and timing data to users
> > worldwide.
> >
> >
>
--
Derek Atkins, SB '93 MIT EE, SM '95 MIT Media Laboratory
Member, MIT Student Information Processing Board (SIPB)
URL: http://web.mit.edu/warlord/ PP-ASEL-IA N1NWH
warlord@MIT.EDU PGP key available
