To: atm{at}shore.net
From: Jim Burrows 
Reply-To: Jim Burrows 


At 14:27 2003-07-21 -0400, James Lerch wrote:

>Ok, Let the FUN begin 
>
>Unit = Waves
>Wavelength = 633nm
>
>RMS Wavefront = 0.145  {46nm Surface}
>PV wavefront  = 0.67       {212nm Surface}
>Strehl Ratio    =  0.44

Mike Peck gave me his guesses for the units, order, and normalization of
the Zernike coefficients (you need all three).  With that information and
the values up to "8th order", the easy computation is the RMS; I
get 0.1484 wavefront, 46.96 nm surface (assuming 632.8 nm wavelength (He-Ne
laser)), close enough for government work.

The sign and value of the third "2nd order" coefficient,
-0.384812 are curious.  The sign could be due to "reflection",
and I wonder if that sign goes through the whole table - might solve the
under/over correction conundrum.  The value should be 1/2R, giving R =
1/(2*.384812*632.8E-6) = 2053.3 mm vs. 111.63" = 2835.4 mm (not close
enough for government work
).  [James, what IS R for the mirror?  I hope one of those values
.]

If we could solve these mysteries, the tough computation of surface height
and slope is possible, first along the reference diameter.  From that we
can derive what Robo-Foucault readings should have been.

         -- Jim Burrows
         -- mailto://burrjaw{at}earthlink.net
         -- http://home.earthlink.net/~burrjaw
         -- Seattle N47.4723 W122.3662 (WGS84)

--- BBBS/NT v4.01 Flag-5