LAYOUT OF CCDs for PA=180degrees
---------------------------------

        chip#1:         Ra -5"    Dec  704"     move telescope W and N
        chip#2:         Ra 1043"  Dec  357"     move telescope E and N
        chip#3:         Ra 10"    Dec -701"     move telescope E and S
        chip#4:         Ra  0"    Dec    0"
        (this is only valid for rot mount 180)

                    N
          +------------------+
          | #3  0.33"/pixel  |
          |                  |
          |                  |
          |                  |
          +------------------+
          +------------------++----------+
          | #4               || #2       |
          |                  ||          |
        E |              RC  ||          |
          |               +  ||          |
          +------------------+|          |
          +------------------+|          |
          | #1               ||          |
          |                  ||          |
          |                  ||          |
          |                  ||          |
          +------------------++----------+
                     +-----------+
                     |    #AG    |
                     |           |
                     |  0.37"/p  |
                     +-----------+
                     |  Masked   |
                     | for frame |
                     | transfer  |
                     +-----------|

The above layout is for Rotator at 180 deg.


IRAF display orientation information

display display the short axis as X
                    long  axis as Y

chip 1, 3, 4

x,y
0,4100      W     2048,4100
      +----------+
      |          |
      |          |
      |          |
      |          |
    N |          | S
      |          |
      |          |
      |          |
      |          |
      +----------+
           E
  0,0           0,2048



chip 2

x,y
0,4100     S     2048,4100
      +----------+
      |          |
      |          |
      |          |
      |          |
    W |          | E
      |          |
      |          |
      |          |
      |          |
      +----------+
           N
  0,0           0,2048



From Mike Irwins's program fits_astrom

      parameter (pixsca=0.3334)

c *** location of rotator centre in pixel space for each CCD
      data xoff/-284.0,3225.0,3931.0,1828.0/
      data yoff/3042.0,1732.0,2998.0,3029.0/


In arcsecs these are:





INT Apertures values that correspnd to various reference points:

  ap 0 -251   326   the nominal aperture, object centered on CCD#4
  ap 1  704     5   center object on CCD#1
  ap 2  357 -1043   center object on CCD#2
  ap 3 -701   -10   center object on CCD#3
  ap 4    0     0   center object on CCD#4
  ap 5 1316  -368   center object on AG-CCD (X=1032, Y=512)
  ap 6  251  -326   center object on RC (rotator center


note apertures cords are in x and y and these are rotated and
reflected with respect to alpha, delta


eg ap 2 x =  0 -1 delta alpha
        y = -1  0 delta delta

    x =  cos theta sin theta   alpha
    y   -sin theta cos theta   delta