Changes
/* Acquiring a target */
or:
'''3(b)''' In the TCS '''Controls''' tab click on the box labelled '''Targets''', then select the desired object from the dropdown list. To populate the dropdown list, see the [[#Target Creating a target catalogue| catalogue instructions]].
The telescope will slew to the target, and its movement will be plotted in red dots on the schematic in the right-hand panel. The "Go" button will become a "STOP" button, which you can click if you need to stop the telescope. Once it reaches the target coordinates, the telescope will start to track and yellow dots will show the track progress on the visibility plot. If nothing happens, the target is probably outside the observing window - return to step 2.
'''4.''' The telescope will track the target until you click '''STOP''', or until it reaches the lower altitude limit (note that the TCS will not warn you if this happens, so keep an eye on the visibility plot).
'''5.''' Lesedi's pointing is excellent, so your target should land very close to the centre of the image. The Due to cable wrap limits that preclude a 360° instrument rotation, the '''image orientation''' will vary between North up, East to the left, ; and North down, East to the right, due to cable wrap limits that preclude a 360° instrument rotation.
To adjust the pointing (e.g. to position a target and comparison star in the field), in the TCS Controls tab, click on the three dots beside "RA offset" (to shift the image horizontally) or "Dec offset" (for a vertical shift), enter the size of the required offset in arcsec, then click on the North, South, East or West button to move the telescope in the desired direction. When you're done, clicking the three dots again will hide the offset boxes.
'''6.''' The focus position is reported in the central status panel on the Controls tab. A reasonable starting point for Mookodi focus (imaging with clear filter) is ~2380μm; ~1700μm for Sibonise. Once you're close to focus, a reasonable increment for small adjustments is ~10μm. Focus the telescope using the '''Adjust Focus...''' button, which brings up a box in which you can enter the focus increment in microns, then click '''+''' or '''-''' to add or subtract e.g. 10μm to the focus position.
=== Creating a target catalogue ===
If you will be observing many targets during your run, or revisiting the same targets repeatedly, it would be helpful to create a target catalogue so that you don't have to type the coordinates into the TCS every time. There are two ways to do this:
# '''Add each target to the catalogue the first time you observe it.''' To do this, click "Catalogue..." enter the target, coordinates and equinox into the boxes and click "Add Target". You can then select the target from the dropdown "Targets" list above the Catalogue button.
# '''Create a catalogue file.''' Create a text file on the PC that is running the browser TCS (e.g. if you are in the dome, this will be lesedi-nuc). The file should consist of one line per target, with RA, Dec, target name & equinox as comma-separated variables, e.g.
11 12 13,-14 15 16,J1112-1415,2000
22 23 24,-25 26 27,J2223-2526,2000
Save the catalogue with an easily identifiable filename, e.g. myname.txt, then on the TCS, click "Catalogue..." and "Import". Navigate to the appropriate directory and select your catalogue file.
If you are observing from the dome, using lesedi-nuc, and have created your catalogue file on your own PC, you will need to upload it using:
scp myname.txt ccd@lesedi-nuc.suth.saao.ac.za:~/Targets
then on the TCS, click "Catalogue..." then "Import" and select your file from /home/ccd/Targets.
If you click on the dropdown Targets list above the Catalogue button, your targets will be available for you to select, then click "Go" to point.
== Autoguiding ==
