"D" <noemail@respondhere.com> wrote in message
news:f9pdv358q4d767lpi21ua63eouhaap4gqa@4ax.com...
> On Fri, 04 Apr 2008 21:12:28 -0400, "Richard B. Gilbert"
> <rgilbert88@comcast.net> wrote:
>
> >Roger 2008 wrote:
> >> "Gordon Burditt" <gordonb.sh6xy@burditt.org> wrote in message
> >> news:XrOdnYKg7an-52vanZ2dnUVZ_vOlnZ2d@internetamerica...
> >>
> >>>>Please do not forget who the original poster was and his questions:
He
> >>>>asked:
> >>>>"can I display my own LAT/LON values somehow without a map application
?"
> >>>
> >>>For some cell phone implementation of "GPS" (this one doesn't involve
> >>>actual satellites talking to your phone), your position coordinates
> >>>are present at the cell towers and somewhere in the offices of Big
> >>>Brother, but not on your cell phone. If a map application can get
> >>>your position at all, it has to ask your cell provider to send it,
> >>>and that may cost money.
> >>
> >>
> >> Oh yeah, now that you mention it. My first camera phone called it GPS
but
> >> when you read further about it, it was just using cell phone towers.
> >>
> >> BTW I have met a person with an iPHONE that thinks his phone has GPS
and he
> >> even showed me "Google Maps for Mobile" on it.
> >>
> >> I thought he had a messed up GPS reading because it had us way across
the
> >> street and then I learned later the iPHONE uses cell phone towers for
an
> >> approximate location on "Google Maps for Mobile."
> >>
> >>
> >
> >GPS, or at least the civilian version of it, is only accurate to within
> >about 300 feet or 100 meters. I once did a "site survey" using a
> >Motorola M12+T GPS timing receiver. The software I used plotted
> >something like 10,000 position readings on the map. The result was a
> >strip about 10 meters wide and 100 meters long and oriented ENE-SSW. My
> >antenna was more or less in the middle of this mess.
> >
> >The military uses a different set of signals from the same satellite and
> >gets accurracy good enough for weapons targeting. This level of GPS is
> >available only to the military and certain defense contractors. Us
> >lowly civilians can't get it.
> >
> >As far as I know, a cell phone tower has no means of determining the
> >direction your signal is coming from.
>
> Towers cannot tell what direction the signal is coming from, but can
> tell from relative power how far away it is, and form a circle based
> on that reading. For sake of argument, say you are 3 miles from
> tower one, and 5 miles from tower two. there are only two places you
> can be 3 milies and 5 miles from the towers. Add a third tower, and
> you only have one place you can be. That is how triangulation (hence
> the tri - three) works.
With no disrespect for the poster that started this thread then how does VOR
for airplanes work from one transmitting site?
More on VOR can be found at:
http://www.pilotfriend.com/training/...v_overview.htm
But the above site doesn't come right out and say if they use more than one
transmitting tower to get VOR to work.
I have been under the assumption that since most cellphone towers have three
elements that the cellphone knew that it was 1 of 3 directions away from the
tower but now it seems there is nothing VOR related in cell phone towers.