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How to check the tertiary mirror position w/ 2 S-H

To check that the tertiary mirror is pointed correctly,
you can run active optics on both probes.

This example assumes that we are at Magellan 2, using probe 1 for normal guiding, probe 2 for active optics, and that we will use the observer's computer, zorro, to make the second active optics measurements.
If the situation is different, make the appropriate substitutions.

In the afternoon, or before observing starts, check the following:

1) Check that gcam1 is set up to send its images to zorro as follows:
    a) Exit the program and change to directory C:\GCAM
    b) copy gczorro1.ini gcam.ini
    c) restart the program with CTRL-ALT-DEL
    d) Make sure to set SH 1
    e) Set the box to the LED position.

2) If you don't already have the second active optics windows running on zorro, start them as follows:
    a) From the operator's workstation, open an xterm, and type ssh zorro activeoptics.csh
    b) Make sure that "load corrections" is set to no in hartpar.
    All the other parameters can be left at their defaults, or the same as the other active optics window.
    c) Type resetcell in one active optics window, wait five seconds, and then type resetcell in the other active optics window.
    d) Start the "hartmannloop" in both windows.


Start observing normally doing normal guiding in probe 1 and active optics in probe 2.  Once the mirror is tuned up, and the image size is at its best, or at any time during the rest of the night, do the following to check the tertiary position:

Stop guiding gcam1, put in the mask, and type send.

(You do not need to start tilt guiding and you do not need to put the probe at the center of the field.)

Compare the numbers for coma and astigmatism. They should compare within a tolerance of
0.010 for coma, and TBD for astigmatism.
If they don't, recalibrate the tertiary position and tilts, and the position of the rotator you are using (by homing), and then recheck.  If they still don't compare, call for technical support.

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