On the TCS:
# Move the '''guide mirror out of beam'''.
# In "Exposures & Guiding" set "ExpTime" ~2s (adjust as necessary).
# Ensure that the XY slides have been initialised (click "Initialise" under XY slides control).
# Open the guide star software (the icon of a star with a long tail).
# Click on a bright star outside of the green circle in the DSS image. NOTE: this chart is centred on the given coordinates. If you have adjusted the position of the target to be away from the centre of the acquisition frame, there will be the same offset in the selected guide star.
# Under "XY Slides Control," click "GoTo GS". The star should appear in the acquisition image. If not, try a different star.
# Under “Pointer" click "Guide Star" , then click on the chosen guide star in the acquisition camera FOV. This will put a blue box around the star and begin guiding. NOTE: if the star is near a hot pixel, that could cause trouble with guiding. Click "Move XY" and click on the star: this will center it (just moving the XY stages, and not effecting affecting the science target).
# To stop or restart guiding (e.g. after brief intervals of cloud), press GUIDE.
# To change exposure times, press STOP, select exposure time from the drop down menu under Expose. '''In the DS9 interface that pops up:'''* From the "Analysis" pull-down menu, select "DSS Server".* In the "DSS Server" window, click on the "DSS Server" menu and select either "DSS@STSCI" or "DSS@ESO". SAO no longer connects.* Enter RA & Dec of target (using colons to separate coordinate units) in 20'x20' field of view and click "RETRIEVE". * Once the field image loads with the target in the centre, choose a relatively bright star outside the circle. Place the mouse cursor over the star and read off the {\bf XY slide} coordinates in the grey info area above the image. '''On the TCS:'''* With the '''guide mirror in beam''', click on "Move XY", then on the target star position in the acquisition image, then on "Zero XY". This centres the field on the target so that the XY slide coordinates will be compatible with those you read off DS9 for the guide star.* Move the '''guide mirror out of beam'''.* In "Exposures & Guiding" set "ExpTime" ~2s (adjust as necessary).* In "XY Slides Control", click "Go To" and enter X and Y slide coordinates of chosen guide star from DS9.* In "Pointers" click "XY+Win+G" then click the chosen guide star. This will centre the guide star on the image, window the chip and begin guiding.* To stop or restart guiding (e.g. after brief intervals of cloud), press "GUIDE".
== TCS operations at the end of an observation ==