Remote observing on TNT+ULTRASPEC from Warwick

This document is meant to be a complete set of instructions for remote observing from Warwick on TNT+ULTRASPEC, referring where convenient to extensive generic instructions for ULTRASPEC. The focus here are aspects unique to observing remotely.

Starting the system

Remote observing is carried out from a PC setup on the left-hand side of the "Cave" as you enter it.

  1. Login under the "ultraspec" username. Please ask a member of the ULTRACAM team for the password.
  2. Open a terminal
  3. Type "tunnel", enter password (please ask a member of the ULTRACAM team for it) when prompted. (See trouble shooting if you are not.) This sets up an ssh tunnel to the drpc on port 50002. Once set up you can for instance ssh to the drpc using a command like "ssh -p 50002 observer@localhost". Similarly "scp -P 50002 observer@localhost: ." would copy the file of interest on the drpc back to Warwick.
  4. Open another terminal (I typically do this as a tab of the first). Type "vnc". Enter the password (please ask a member of the ULTRACAM team for it) when prompted. If successful, a replica of the drpc screen should appear. Stretch this out to cover both screens (might have to "unmaximise" since it only seems to maximise to one screen). If typing "vnc" fails does not prompt you for a password, check that the ssh tunnel started up successfully.
  5. If all has worked, you are now essentially at the same place as if in Thailand, albeit on a slow network. Type slowly, wait, don't get ahead of yourself! You might well want to kill the status monitor that unnecessarily adds to network traffic. "killall gkrellm" should do the trick.
  6. Before starting the observing system, open a terminal on the rack (double click the rack icon). cd to "/data", check for and run###.dat or run###.xml files. If there are any, check they have been backed up (open terminal on drpc, type "df -h" to find usb drives, navigate to where they are and look for corresponding date). If backed up, delete the run*.dat and .xml files in /data. If they are not, create a sub-directory of /data and move the files into it before proceeding. Let me know if this is the case.
  7. Especially if this is the first night of a run, check for any observing-related processes on the rack (camera, filesave, slogger, FileServer, Lakeshore, usdriver). These need to be closed down before starting the observing system. You will have to kill them ("kill -9 "). Take care when killing processes not to kill important ones!
  8. On a rack terminal, start the observing system, "start_uspec". Windows corresponding to all the previously listed processes, bar slogger, should appear. Check that they seem OK. On the right-hand side of the dual screen, I normally get emacs going to edit the night log (see usual observing instructions). I typically don't run "slogger" all the time because of its frequent updates, but it must be run after the final run is complete before archiving.
  9. You are now in the standard observing mode and at the point where it best to look up the standard documentation on ULTRASPEC at the TNT. Here are some relevant links: There are a few other things worth knowing, some specific to remote observing that I list below.

Starting the night

  1. For the Jan 25/26 run, we started at about 10.00am UK time. First thing to do is to establish contact via skype with the control room. The account is "Controlroom TNO". If you have problems, try e-mailing operations@narit.or.th
  2. Once you have contact, tell the TO that you want to take biases, and could M4 be set to the 4k camera and the dome be dark. They might want to fill, or be filling the LN2 dewar, but should tell you.
  3. It's a good idea to make a target list (using the telescope coordinates from the usfinder charts), so you can send it to the TO. Format: 
    WD0145+234 , 01:48:03.74 , +23:39:16.4
NLTT-11748 , 03:45:26.61 , +17:48:34.5
    although you might want to keep your own version with the position angles as well.
  4. Set the focal plane slide to block, put the u' filter in. Take biases, certainly 1x1 and 2x2 fill-frame clear ones, but also any matching setups from the previous night if need be. Remember if you get bad weather in the night, that can always be a good time for biases. At the send, remove the focal plane mask, ask the TO to point to a blank field.
  5. Again for the Jan 25/26 run, we were able to start flats at around 11:30 to 11:40 UK time. Remember ask the TO to point to blank field, and, once the exposure level is about right, to spiral the telescope.
  6. When on target, you will need to adjust the position to maintain a fixed X and Y as can be judge from the reduce plot. The script "tweakoffset" (maybe "tweakOffset") should help. It is available as an icon on the left of the screen. You just type in the number of pixels you want to move and the PA and it comes back with the number of arcsec to ask the TO to move. You will need to do this rather often annoyingly.
  7. Don't forget also to test the focus on every target. It might help to plot the seeing of both the target and the comparison, esepcially if the target is faint. I tend to move in chunks of 0.03 to 0.05 (focal position can be seen on usdriver). So you tell the TO to go to -89.7 or whatever. Do not be tempted to leave off the sign as they will take you literally!

Trouble shooting

  1. "tunnel" does not work The drpc may not be booted. You need to ask the TO whether it is working, and possibly to re-boot it. If that doesn't do it, send an e-mail to vikcam, addressed to Paul Kerry in case he is around to help.
  2. drpc desktop freezes This might indicate that the vnc connection has gone down. Click "activities" in the top-left of the Warwick PC, and raise the original terminals where you typed "tunnel" and "vnc". The "tunnel" one may show that the connection has dropped. If so, try to re-establish the connection by typing "tunnel" again. It may say say "connection to port 50002 refused" or something for a few times, but persist, because it is a little slot to re-establish. Any run you have going will keep running, and you may have to ask the TO to stop the run if you can't get things going again.
  3. reduce plot screwy a change to ignore bad times for hipercam has a bad effect for ultraspec. You may have to start with first=5 to get past riduculous times in the past. I do hope to fix this at some point.
  4. vnc comes up entriely black. Matthew had this. It *might* have been the result of his using a weird keystroke combination to switch between virtual desktops (don't!), but this isn't certain, and in this state probably only the TOs can fix things.

Tom Marsh