Re: [ATM] Trefoil caused by lateral supports

[Dale Eason <atmpob@yahoo.com>]

The errors are refering to a perfect parabolic
surface.  The analysis depends on a relative
difference between two setups so the absolute surface
does not matter.  I'm looking only at the change.

However, I know low order errors like astig and
trefoil well as explained slightly in the companion
doc.

I think I know low orders to better than 1/20 wave pv
on the wavefront.  The technique involves rotating the
mirror on the test stand and processing the data in
such a way that it removes the test stand and other
system induced errors.  Then isolated the low order
terms using Zernike Polynomials.

The same technique was used to produce my real
Foucault to simulated Foucault analylsis that I
published a few months ago.

 See http://www.atmsite.org/author.html

Specifically:

http://www.atmsite.org/contrib/Eason/Simulation/foucault_sim_surface

http://www.atmsite.org/contrib/Eason/barry8/index.html

Dale Eason


--- Arjan te Marvelde <arjan.te.marvelde@hetnet.nl>
wrote:

> Dale,
> 
> How well do you know your reference surface? I.e.
> what are the errors you
> measure referring to?
> 
> Arjan te Marvelde
> 
> > Here is my analysis of trefoil caused by 2 peg
> lateral
> > support.
> >
> >
>
http://doeason.home.comcast.net/lateral_test/trefoil.pdf
> >
> > This should be studied further to see how
> de-centering
> > on the edge center of mass changes it.  I will try
> to
> > do that.
> 
> 



 
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