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From: will@anasazi.UUCP (Will Fuller)
Newsgroups: net.space
Subject: Re: Phase conjugation
Message-ID: <500@anasazi.UUCP>
Date: Fri, 24-Jan-86 10:40:39 EST
Article-I.D.: anasazi.500
Posted: Fri Jan 24 10:40:39 1986
Date-Received: Sun, 26-Jan-86 20:19:28 EST
References: <860120-145927-1076@Xerox>
Reply-To: will@anasazi.UUCP (Will Fuller)
Organization: Anasazi, Phoenix Az.
Lines: 22

In article <860120-145927-1076@Xerox> Lynn.es@XEROX.ARPA writes:
>One would need a laser in the field of view (on a satellite, say) to
>determine the distortion during the trip down through the atmosphere...

One big problem with the atmosphere that can't be gotten rid of
is the attenuation at certain wavelengths. If you had a tunable dye
laser, you might be able to account for the degree of attenuation,
but if you can't see it...

Real time extinction information is of comparative little value (unless one
is being astronometric). Instead the air mass can be made to work in your
favor - as is the case of speckle interferometry.

What advantage would a space borne laser in the field of view of a telescope
have over any star in correcting the abberations caused by the air mass?
The star might be "calibrated" by a space based detector.

Further, the "spot" from such a remote laser (geosynchronous) would be
damned big...
-- 
William H. Fuller
{decvax|ihnp4|hao}!noao!terak!anasazi!will