Acquiring a guide star

  This procedure discribes the acquisition of a guide star with the guide probe after a guide star is positioned near the centre of the probe field. A full description is given in section .

• If not yet done, switch on the autoguider. If no `idle' message appears press the SHUTDOWN button on the Autoguider Panel.
• Select the autoguider probe image on one of the TV monitors (there is also a dedicated mini-monitor).
• Press the FIELD button on the Autoguider Panel. An image will appear in the autoguider sub-display.
• If you are happy with the selected guide star, press ACQUIRE. Either the probe or the telescope is moved, depending on the chosen acquisition mode, in order to position the star at the centre of the autoguider field. On the monitor a message `pulling-in' will appear after a while.
• When the error drops below a preset threshold, scanning ceases and a message `OK to Guide?' will appear on the monitor. If you are satisfied with the image press GUIDE.
• Wait until the autoguider display is completely redrawn and then press the LOOPENABLE button which should turn green.

  When the cross (the measured star position) is centred in the circle you are ready to observe.

On source change, press WAIT (the guide probe is automatically switched to LOOP DISABLE).