[ATM] ATM: FringeXP comparison to professional software

[koehler at securecomputing.com (Stephen C. Koehler)]

Ric,

> Can you expand on what/how phase shift testing
> works,and what makes it more accurate?

As I understand it, a static fringe interferometer takes a photo of the
fringes in one position.  A phase shifting interferometer slowly shifts
the phase of the source to scan the lines across the optical surface.
A video image(?) of this is taken, and the analysis makes use of the extra
data to get a more accurate model of the aberrations.  I think it is 
equivalent to taking many static interferograms with the lines in 
different places.  As Mike Peck mentioned, you can improve the accuracy
of static fringe interferometry by taking more images.
-- 
Steve Koehler
koehler@securecomputing.com