>How do you know that the CCD is seeing a laser dot and not some other bright
>dot of light?

With a CCD, you can measure the dot.  If it's not the size of the laser
(within reason), you got the wrong dot.  Also, the color would be a good clue.

>Isn't a CCD kinda expensive?

They are pretty cheap any more.  Any small camera module (<$100) will do it.

>Can you modulate the Lasers and use a photo diode with a filter with Q at
>modulation frequency directed by a mirror on a pager motor? the filter
>output pluses only when it sees the correct frequency and the time between
>the two pluses is proportional to the distance.

Don't know - why not give it a try?

Andy

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Andy Kunz               Life is what we do to prepare for Eternity
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andy@rc-hydros.com      http://www.rc-hydros.com     - Race Boats
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