Newsgroups: comp.robotics
Path: brunix!uunet!decwrl!netcomsv!netcom.com!nagle
From: nagle@netcom.com (John Nagle)
Subject: Re: Laser rangefinder (was: IR rangefinder source)
Message-ID: <nagleC576IJ.7HE@netcom.com>
Organization: NETCOM On-line Communication Services (408 241-9760 guest)
References: <DAC.93Apr8150723@locust.frc.ri.cmu.edu> <HABA.93Apr9004233@lesti.hut.fi> <1993Apr8.231214.21663@mksol.dseg.ti.com>
Distribution: comp
Date: Fri, 9 Apr 1993 03:47:06 GMT
Lines: 18

strohm@mksol.dseg.ti.com (john r strohm) writes:
>In article <HABA.93Apr9004233@lesti.hut.fi> haba@lesti.hut.fi (Harri "Haba" Suomalainen) writes:
>>In article <DAC.93Apr8150723@locust.frc.ri.cmu.edu> dac@frc.ri.cmu.edu (Daniel Christian) writes:
>>How do the laser range finders work? Could one be built "easily" from
>>surplus lasers? (Half joking, half serious..)
>The laser rangefinder I saw on one project worked by bouncing a laser light
>pulse off the target being ranged, and measuring round-trip time.  This 
>requires a pretty narrow pulse, which in turn requires a pretty high
>pulse power.  For eye-safe, this one was an infrared (CO2) laser, and it
>was purpose-built.
>Unless you have a suitable pulsed IR laser handy, with a suitable pulse
>width, you probably don't want to try it.

       Nah.  It's possible to do it with a 5mW laser diode.  Not
easy, but it's been done by several people.  I've posted details in the
past on how.

						John Nagle
