Subject: Re: Can Microwaves Be Used To Collect XYZ Coordinates
From: ganter@ifi.unibas.ch (Robert Ganter)
Organization: Institut fuer Informatik
Nntp-Posting-Host: schroeder.ifi.unibas.ch
Lines: 63

In article <1993Apr15.103953.66252@cc.usu.edu>  writes:
> In article <C5Hs5J.AG7@bcstec.ca.boeing.com>, rgc3679@bcstec.ca.boeing.com  
(Robert G. Carpenter) writes:
> 
> |> It seems reasonable to me that a microwave transmitter-receiver setup  
could 
> |> do the job. For example, say you want to map an acre lot, it'd be  
convenient
> |> to place MW transmitters around the lot's periphery (either 2 or 3) and  
then
> |> carry a hand-held recorder and walk to a point on the lot, press a button  
and
> |> the coords of the recorder's location is stored as digital data.
> |> 
> |> What's the chance of this working? Any systems like this already exist?
> |> What kind of accuracy could you expect? What would something like this
> |> cost to prototype? Is there a better alternative than microwaves?
> 
> Of course you could develope this system, but there is already a system  
called Global
> Positioning Satellites.  It gives three dimensional coordinates anywhere on  
earth. 
> Many surveyors use this system with a differential receiver/transmitter to  
get
> coordinates within centimeters.  Basic receivers with resolution of a few  
meters (on
> a good day) are available from many sources.
> 
> 
> -- 
> WMWMWMWMWMWMWMWMWMWMWMWMWMWMWMWMWMWMWMWMWMWMWMWMWMWMWMWMWMWMWMWMWMWMW
> 
>   \_      \_  \_\_\_    \_\_\_               Weston R Beal
>    \_      \_  \_    \_  \_    \_         sldf3@sol.ee.usu.edu
>     \_  \_  \_  \_\_\_    \_\_\_            sldf3@cc.usu.edu
>      \_\_  \_\_  \_  \_    \_    \_       Electrical Engineer
>       \_      \_  \_    \_  \_\_\_       Utah State University
> 
>   "That's the wonderful thing about crayons; they can take you to
>    more places than a starship can."    - Guinon
> 
> 

Thought it means Global Positioning System. There are two precision levels, one  
for army applications (killing has to be very accurate today) and one for civil  
ones. The civil precision is about 20 to 30m (correct me, if I'm wrong),  
though, it may be insufficiant for mapping buildings. But there is a way with  
an additional reference point (e.g. one fixed GPS system in a house) to get the  
same high precision as the military version, but it gets pretty complicated  
then. If You use a microwave system (actually this means some type of radar),  
You need quite a lot of number crunching to get accurate vectorized data out of  
Your original signals. So the GPS system seems to be the better (and running)  
idea for Your application(there have been discussions in this newsgroup, don't  
know of an address anymore).

Cheers    Robert   (HB9NBY) 
--
Robert Ganter			/------------\
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