===============================================================
Misalignment measured last 3rd March 2002 with the pupil imager
===============================================================

I have measured the central position of the of the secondary and the pupil
stops in the pupil imager images in order to have more accurate
measurements of the misalignment (not affected by the differences in size
of the pupil stop central obscuration).
The results are given below.
There seem to be an aprox. constant misalignment of the pupil stops with
respect to the secondary mirrow (as we saw by eye). It is equal to ~375
microns (pupil stops down).

There is also a small misalignment in the direction of movement of the
pupil stops (left-right), which changes from one to another and that could
be produced by the movement of the filter wheel. In fact, two different
measurements of the same pupil stop (cass-k), give a different misaligment
in x (left-right) and the same in y (up-down).


==================================================================================
p stop        SECONDARY        |             PUPIL STOPS
                               |
           center      radius  |   center   obs. radius   outer radius   measured
           (x,y) pix    (pix)  |  (x,y) pix    (pix)      (pix)   (mm)     scale
			       |  					  (mm/pix)                       
==================================================================================
cass-j   (461.5,549.3)   133      (455,535)    150        488    11.96   0.0245 
cass-h   (462,549)       133      (465,534)    144        484    11.96   0.0247 
cass-k   (448.5,552.3)   133      (450,534)    143        494    11.96   0.0242     
cass-k2  (462,549)       132      (462,534)    142        490    11.96   0.0244 
cass-s   (463,548.8)     134      (463,533)    137        486    12.63   0.0260 


------------------------
            Misalignment  (=diff. in central position of secondary & pupil stop)
              (pix)
            x        y   
------------------------
cass-j    -6.5     -14.3  
cass-h     -3       -15
cass-k    -1.5      -15  
cass-k2     0       -15
cass-s      0      -15.8

-negative misaligment in x means that pstop is 
 shifted towards the left of the secondary
-negative misaligment in y means that pstop 
 is shifted down of the secondary

Therefore assuming scale is ~0.025mm/pix ==> mean missaligment is ~375
microns pupil stops down.


Missalignment of the secondary with respect to the center of the chip (512,512)
---------------------------------------------------------------------

p stop        SECONDARY        
                               
         center      radius |    missalignment                missalignment
         (x,y) pix    (pix) |   center chip-second        center chip-pupil stop
                            |  (x,y) pixels   (x,y) mm    (x,y) pixels   (x,y) mm
=================================================================================
cass-j  (461.5,549.3)  133   (50.5,-37.3)   (1.26,-0.93)  (57,-23)  (1.43,-0.58)   
cass-h  (462,549)      133   (50,-37)       (1.25,-0.93)  (47,-22)  (1.18,-0.55) 
cass-k  (448.5,552.3)  133   (63.5,-40.3)   (1.59,-1.01)  (62,-22)  (1.55,-0.55) 
cass-k2 (462,549)      132   (50,-37)       (1.25,-0.93)  (50,-22)  (1.25,-0.55) 
cass-s  (463,548.8)    134   (49,-36.8)     (1.23,-0.92)  (49,-21)  (1.23,-0.53)