On 6/07 Micheal Connelley did moris engineeing:

Here is MC's report: MORIS_platescale.pdf

  1. Measured Moris's Platescale: 0.1141 as/pixel.
  2. Spex's platescale is actually: 0.1156 as/pixel.

  2. Map Spex's Pixel's to Moris Pixel. Spex XY located can be 
     map to moris via 2D translation using:

    Transpose XY: 61 44
        Scale XY: 1.01315  1.01315
         Rotate : 1.2 degs


s.txt are spex  centroids from 10 stars in ngc6366.spex.0002.a.fits.
m.txt are moris centroids 10 stars in from ngc6366_0062.a.fits.

 

t.c is code to rotate, scale, transpost to get s.txt close to m.txt.

   Transpose spex XY by tx=-256, tx=-256.
   Transpose data    by t_x=61,  t_y=44, scale_x=1.01315, scale_y=1.01315, rotate=1.2 deg
   Transpose data XY by tx=+256, tx=+256.
   Resulting data is written to x.txt.

 
plot.png shows m.txt vs x.txt
   where m.txt is moris position.
         x.txt is spex's translated position.

   Here are the gnuplot command to make the plot:
      set yrange [0:512]
      set xrange [0:512]
      plot 'm.txt' using ($2):(512-$3) with line
      replot 'x.txt' using ($2):(512-$3) with line