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From: smith@sndpit.enet.dec.com (Willie Smith)
Newsgroups: comp.robotics
Subject: Re: Getting narrow-beam range data
Message-ID: <1290@sousa.ltn.dec.com>
Date: 7 Jun 91 19:52:22 GMT
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Organization: Digital Equipment Corporation
Lines: 19


In article <77904@brunix.UUCP>, kjb@cs.brown.edu (Ken Basye) writes...
>We're looking for a way of getting a single range measurement in a
>particular direction.  We have sonar, but the beam is far too wide.
[...]
>Ideally, we'd like something that has low power consumption, a 5-10
>degree cone (or less) and a range up to at least 4 meters, although it
>need not be very accurate (even +/- 10 cm would be OK).  
What's wrong with sonar again?  The Polaroid sensors have a beam width of 
something like 12 degrees....

I called Polaroid the other day and they mentioned that the beamwidth is 
approximately inversely proportional to transducer size, and one way to get 
narrow beamwidths is to use arrays of transducers.

Willie Smith
smith@sndpit.enet.dec.com
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