[ATM] AO for the Amateur

[Paul Kline <paul.kline@DRAKE.EDU>]

As pointed out at http://cfao.ucolick.org/ao/ AO can be of either real-time 
or post-processing mode.  The first requires an adaptive element.  With 
smaller optics a sharp image simply wanders around the focal plane and the 
eye+brain does a credible job of following it, or a tip-tilt mechanism 
works to take great photos.

For fairly inexpensive and well-demonstrated examples of post-processing 
with small optics and ccd imagers see http://www.qcuiag.co.uk/

For large static optics in less-than-ideal seeing a sharp image never 
exists, that's why they put them on mountaintops.  Or sell a mountaintop 
and build an AO.

Since the really-big AO solutions involve warping sections of a large 
flexible mirror, you could sneak up on the problem by:
   1.  making a high-f spherical 8" mirror
   2.  cutting two 3" mirrors out
   3.  making them both tip-tilt
   4.  making them work together as a single mirror while separated 12"

#4 is where it gets hard.  You have to effectively align the surfaces 
within 1/4 wavelength, as though they _were_ a single mirror.  Your 
tip-tilting is computerized right?  So every few micro-seconds you put them 
in a rest position and unshutter a laser-interferometer for a quick check.

Your resolution would approach an 18" mirror though a bit dimmer.  Planets 
and moons?

There are lots of problems, but at this size you won't break the bank.  You 
might even succeed, in which case we'll all want one - flexed, bartelized, 
AO'd, and fits in a briefcase :-)

On the other hand, if you've got money you can follow in the footsteps of 
these folks:
http://www.fas.org/spp/military/program/track/msss.pdf
http://medusa.as.arizona.edu/lbtwww/tech/salinari.htm
http://www.opticsinfobase.org/abstract.cfm?id=78407
http://optics.nasa.gov/adap_optics/pamela.html
http://imaging.creol.ucf.edu/publications/Phased_Telescope_Arrays.pdf

Paul Kline
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