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40" / 1.0m

494 bytes removed, 10:46, 23 April 2019
/* Acquiring a target */
# The RA & Dec zeropoints will be displayed in the message box. Note them down with the HA & Dec as you will need to re-enter them using "ZERO POINTS" → "Enter Zeros Directly" if the TCS software is restarted, or if you return to this part of the sky after using different zeropoints in a different position. You do not need different zeropoints for different equinoxes. There is no need to note the collimation coefficient as it is ignored by the pointing model.
=== Acquiring a target ===
# Follow the facility [[#Start-up recipe|start-up procedure]].
# '''Initialise''' the XY-slides.
# Move the '''guide mirror into the beam'''.
# Click "TARGET" and type the RA & Dec of the target into the appropriate boxes, then click "SET" and "CLEAR". The coordinates will appear in yellow in the monitors above the TCS and on the observing floor to help you point to the target. (If you cannot see a "TARGET" button, click the "O" in the left-hand corner below the "SET EQUINOX" box.)
# Type the '''equinox''' of the target coordinates into the "SET EQUINOX" box and press "ENTER" on the keyboard.
 '''At the blue console by the North pier:'''# Switch Click "TARGET" and type the central toggle switches to FAST.# Use the yellow RA & Dec buttons to slew to of the targetinto the appropriate boxes, watching both ends of then click "Auto" to slew. (If you cannot see a "TARGET" button, click the telesope as well as "O" in the coordinate display monitor. You should point to within 30s (RA) and 1left-2 arcmin (dec) of your target coordinates.# Switch hand corner below the central toggle switches to SLOW to commence tracking"SET EQUINOX" box.  '''Back at the TCS:''')
# Set "Exp Time" to ~2-4s and "WINDOW" to "Full frame" to take images with the acquisition camera.
# Use the hand paddle arrow buttons in the bottom left of the display for fine adjustment of the telescope to the target's coordinates while watching the image display for to centre the target field to appear. Comparison with an 8x8 arcmin finderchart is most helpful.
# The position should be accurate if you have followed [[#Determining pointing offsets using a bright star|this procedure]], so check your zeropoints. If not, adjust "Exp Time" to search for patterns in fainter stars to compare with your finderchart. If this fails, then reduce the exposure time and scan the field by systematically adjusting RA & Dec.
# Once the target is identified, move the guide mirror out of beam and position it on the image display such that it falls target on the centre of the science CCD(STE3/4 or SHOC).
* '''For STE4''', position the star approximately on coordinates (210, 270) of the TCS image display, to coincide with the centre of the science detector (for '''STE3''', approximately (180,190)).
'''On the instrument PC:'''
* Take a snapshot (STE3/4) or preview (SHOC) to check the positioning of the target on the detector and adjust using the handsetarrow buttons on the TCS.
* Using '''STE3/4''', video mode can be invoked by clicking "Snapshot", entering an integration time, selecting "Video" and clicking "Ready". It can be stopped by clicking "Snapshot" and "Stop". Video mode automatically prebins the CCD, so remember to change back to 1x1 afterwards, if appropriate.
'''or'''
* '''For a long run or for exposures ≥100s, you should locate a guide star and setup set up the autoguider before integrating on your target.
== Finding a guide star & autoguiding ==
Hannah
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