Path: utzoo!attcan!uunet!lll-winken!lll-tis!ames!ncar!tank!oddjob!uwvax!rutgers!mit-eddie!uw-beaver!tikal!amc!richm
From: richm@amc.UUCP (Rich Moran)
Newsgroups: sci.electronics
Subject: Re: To build a cheap RF location tracker?
Message-ID: <753@amc.UUCP>
Date: 8 Sep 88 23:58:27 GMT
References: <831@sybase.sybase.com> <804@ns.UUCP>
Reply-To: richm@amc.UUCP (Rich Moran)
Organization: Applied Microsystems Corp., Redmond, WA.
Lines: 13

In article <804@ns.UUCP> logajan@ns.UUCP (John Logajan x3118) writes:
>Joseph Weinstein writes:
>> I have an need for a position tracking device, for an
>> area no bigger than 1/4 mile x 1/4 mile.
>
>Personally I would go with ultrasonic pulses -- and use the
>arrival time difference at several sites to compute location.
>

Since the speed of sound varies with temperature, humidity and
movement within the medium (wind), the ultrasonic method can have
some problems.  The temp and humidity problems can be nulled
by having a reference distance which is measured along with the
targets, but wind is a toughie.