== Autoguiding ==
As of February 2021, there is a web browser interface to the standalone autoguider control GUI run on 1ms1, so users no longer need to VNC to Lesedi-NUC. Note that the original autoguider software does need to be running on Lesedi-NUC in order to operate the guider, but you shouldn't need to interact with it directly. The procedure for autoguiding via the browser is described below.
Open a web browser and navigate to:
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[[File:lesediAutoguider.png|thumb|400px|frame|left|The web browser interface for Lesedi's autoguider (click to enlarge).]]
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The autoguider camera image is displayed on the top right, with the finderchart image below. There will be a green "Online" indicator at the top left if all is well; if it's red ("Offline") the web server may not be running (see instructions above) +++++++ or the autoguider control software might not be open on Lesedi-NUC. The autoguider camera image is displayed on the top rightIf it looks ok, with continue reading this section, otherwise skip to the finderchart image belownext section+++++++.
To acquire a guide star, do the following:
# Click "INITIALISE" to return the XY-slides to the home position.
# In the terminal running the web server, press CTRL-C to kill the process.
=== Backup Autoguiding Procedure ===
Some users have encountered repeated loss of connectivity issues that make it very difficult to use the browser control for autoguiding. In this case, you can interact directly with the backend software by following the instructions below.
# Connect to the NUC via remote desktop, e.g. for Linux use the Remmina client, set the server to lesedi-nuc.suth.saao.ac.za and enter the username and password from the Lesedi User Resources Google document.
# Once connected to Lesedi-NUC, the autoguider software should be running. If it isn't, or if it fails to respond, follow these instructions.+++++++
To start guiding:
# On the main autoguider GUI, if using SHOC select Slide 0; or Slide 1 for Sibonise.
# If the status of any of the error codes (Err, XLL, XUL, YLL or YUL) is 1, click RESET, then INITIALISE. "FAKE" should always be a green "Fake is OFF" button while guiding - this is a test function for engineering purposes.
# To start continuous exposures with the autoguider Lodestar camera, enter a number (~2 seconds) in the box on the right, and click CONTINUOUS. Binning should be set to 2x2. To get a workable look-up table, on the left-hand side of the main autoguider GUI, move the uppermost vertical slider ~1/6 of the way from the bottom. Leave the other two sliders in their default positions (lower vertical slider halfway up; lower horizontal slider all the way to the left; upper horizontal slider all the way to the right).
# Enter the target coordinates (using spaces as delimiters, e.g. 12 34 56 -76 54 32) in the separate GS_FC window and click "Set".
# Check that a finder chart loads showing your field. Guide stars are to be selected from outside the green box in the finder chart image. When North is Up in the SHOC/Sibonise image, click on a star in the upper half of the image to use as a guide star.
<!--, with X<20000 and Y<15000. As Y approaches 10000 it begins to vignette the SHOC field, so try to choose a guide star at low Y.-->
# On the XY Slide Control section of the main GUI, click "Goto GS". This will send the XY slides to the position you clicked on the finder chart. <!--If it doesn't, read the coordinates of the guide star off the image and enter them manually; when the position is reached click "Pick guide star" and click on your chosen star in the guide camera image.-->
# Click the "Pick G_Star" button in the "Guiding" panel, which will turn dark blue to indicate that it's ready to receive your guide star selection.
# Choose a star in the Lodestar image and click on it. The "Pick G_Star" button will turn green if it recognises the star. If the button turns grey, your selection has been unsuccessful and you will need to click the "Pick G_Star" button again and then try clicking on a different star.
# Click the red GUIDE button - it should turn green to indicate that it has started guiding.
'''If guiding fails''' at any point during a track (e.g. due to cloud), the button will turn red. Try increasing the exposure time (change the value and click "CONTINUOUS") and click GUIDE if the star is sill near the box. If the star has drifted, you can either offset the telescope to bring it back to its original position and then click GUIDE, or if it is not important to you to keep the target in the original position on the science image, you can repeat the guide star selection procedure to resume guiding in the new position.
To stop the autoguider:
# Click "GUIDE" to stop guiding.
# Click "STOP CONT." to stop exposing.
# Click "Initialize" to return the XY-slides to the home position.
=== Autoguider troubleshooting ===
If the autoguider GUI isn't already running (or is not responding), open a terminal, login to 1ms1 (username & password in the google doc) and check for any autoguider jobs already running:
ssh -Y observer@1ms1.suth.saao.ac.za
ps aux | grep readPLC
If there are outstanding jobs, the result will be something like:
root 1310 99.8 0.1 39384 13016 ? R Jun21 5284:08 python readPLCandLesediV1.py
root 14103 0.0 0.1 39384 13040 pts/11 S+ 14:41 0:00 python readPLCandLesediV1.py
root 20411 99.9 0.1 39384 13092 ? R Jun23 1187:37 python readPLCandLesediV1.py
observer 25808 0.0 0.0 14224 1032 pts/12 S+ 17:49 0:00 grep --color=auto readPLC
These processes remain "hanging" if the xyslides software was not closed properly using the EXIT button. You need to kill them using their IDs given above, e.g. in this case:
sudo kill -9 1310 14103 20411
Then in the same terminal, check that the Lodestar cameras are connected:
observer@sa1:~$ lsusb
Bus 002 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
Bus 001 Device 079: ID 1278:0507 Starlight Xpress Lodestar autoguider
Bus 001 Device 081: ID 1278:0507 Starlight Xpress Lodestar autoguider
If you do not see the Starlight Xpress listed then the cameras are not detected on the USB ports and the icron devices probably need power cycling.
Once any rogue processes are killed and the cameras are connected, start the autoguider GUI:
cd /home/observer/xyslide_lodestar_GUI_testing
sudo ./main_prog -depth 24
If you intend to run the autoguider from the browser you don't need the next step, but follow it if you will be interacting with the backend software. To run the finder chart software, open a new terminal (or a new window in the same terminal with CTRL-SHIFT-T) and login again to 1ms1:
ssh -Y observer@1ms1.suth.saao.ac.za
cd /home/observer/GS_FC
python genfinderLesediFeb2020.py
This brings up a finder chart and a coordinates box.
== SHOC on Lesedi vs. other SAAO telescopes ==