Path: utzoo!utgpu!news-server.csri.toronto.edu!rutgers!usc!samsung!dali.cs.montana.edu!milton!whit
From: whit@milton.u.washington.edu (John Whitmore)
Newsgroups: sci.electronics
Subject: Re: Objects in three-space
Message-ID: <13322@milton.u.washington.edu>
Date: 20 Dec 90 10:41:13 GMT
References: <1990Dec19.202741.24898@sbcs.sunysb.edu>
Distribution: usa
Organization: University of Washington, Seattle
Lines: 18

In article <1990Dec19.202741.24898@sbcs.sunysb.edu> mmoss@csws8.ic.sunysb.edu (Matthew D Moss) writes:
>
>  I am starting a project that will require locating some
>object (transmitter, reflector, or something) in three-space

	Almost any old book on radar would help with basic concepts.
You might consider making your 'object' a radio receiver.
Then transmit to it a swept-frequency audio tone.
When a microphone at the triangulation station receives an in-phase sound
input, the object is exactly an integer number of audio wavelengths
from the interrogator.  You can sweep the transmitted audio signal
and time the phase-matching times (using a phase comparator)
with respect to the audio frequency, to tell the distances.
	Of course, this could be done with various other 
energy sources, but an AM radio makes a readybuilt easy 
beacon for your object, I would think.

	John Whitmore