Hi All,
Regarding several recent posts about systems for providing folks
with their current location, the use of cell phones and the cells
themselves is probably not close enough to be better than you
already know.  Since the cells do not have any directional
location capability, all they can do is compare relative signal
strengths.  I'd be very surprised if you'd get better than a
quarter mile resolution that way.

There are the beginnings of rumors about including GPS
receivers in cell phones, but so far as I know no standard for
sending the GPS data over the cell phone.  This is one area where
the ham radio folks have taken the lead with a system called
APRS, for Amateur Packet Reporting System.

None of this is very close to being ready for prime time, so
don't hold your breaths.

As for the automobile based mapping systems, look up an actual
review, they don't look so good when tried by the real world.
They all suffer from the basic problem of GPS, the more buildings
around, the less well it works.  This is basic to any satellite
technology and is unlikely to be fixed by fancier receivers.
Most folks in this area are using a combination of GPS and some
version of inertial navigation which can tell how far/fast you're
moving in what direction.

Here at Smith-Kettlewell RERC we're looking at a cell based
system which might, might, be able to let you carry a very small
camera and send a picture of your current location to a "remote
sighted guide."  This is still very very preliminary, don't even
ask when you can have one, you can't.  The purpose here would be,
for example, when you know you're close to a desired destination,
but just can't find it.  A "remote sighted guide" might be able
to see something useful.  Yes there are a very great many if's
and's and but's so don't yell at me, it's just a beginning.

If the entire world was well plastered with Talking Signs, much
of this blather would go away wouldn't it.

Hope that clarifies things a bit?
Tom Fowle WA6IVG Smith-Kettlewell RERC.


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