Remote Observing with CHARA
For remote observing, we are running a virtual machine on the CHARA server in Atlanta. The machine runs all the graphical user interfaces (GUIs) for the control software that is used in remote observing. These GUIs connect to their respective servers on Mt. Wilson using a process called SSH port forwarding (often referred to as SSH tunneling). This virtual machine also runs a VNC server so it can be accessed from anywhere. This system is currently functional and has been tested for operations with the Classic, CLIMB, JouFLU, MIRCx, and PAVO beam combiners. The software for VEGA has been installed and will be tested on sky soon.
Arranging Use of the Remote Observing Machine
Connecting to the Remote Observing Machine
- Download and install a VNC viewer. We recommend tigervnc ( http://tigervnc.org/ ) because of the viewers we’ve tested, it runs the fastest. Others do work, though.
- If using tigervnc's viewer, run the vncviewer command. This should open a window that looks like this:
- Input the address you are given into the "VNC server" prompt. This should bring up a password prompt. This will connect you to the Atlanta remote observing machine.
- If you get the error "unable to connect to host: Connection timed out (10060)", you are likely behind a firewall and should try again from another network or get in touch with your IT people to open up the 5900 range of ports (5900-5999).
Notes on tigervnc
- tigervnc only allows one active viewer at a time to connect, so if you want multiple connections to the Atlanta machine, you can use the “view only” password (given upon request), but as the name suggests, that only allows you to view what the active user is doing.
- The tigervnc VNC viewer can be spread out over multiple monitors and made fullscreen. Use the F8 key to open the context menu to see more options and to exit out of fullscreen.
Check the SSH Tunnel
- The SSH tunnel should start automatically at 4pm Pacific time and disconnect at 8am.
- If the SSH tunnel is not connected, GUIs will either not open or will be riddled with errors due to the fact that there is no communication between GUIs and their servers on the mountain.
- To confirm that the SSH tunnel is running, run the Check SSH Tunnel script from the desktop icon or the Applications/CHARA menu.
- This script will tell you whether the SSH tunnel is running or not and give you the option of starting or stopping it.
The following GUIs are available for use and accessible through the Desktop icons or the Applications/CHARA/ menu:
- Cosmic Debris (primary and secondary)
- OPLE (primary and secondary)
- Lurking Telescopes - smaller GUIs that allow less control, but take up less screen space
- CLIMB (1 and 2)
- MIRCx (server, rtd, sequencer, and gdt)
- VEGA (power, tracker, detectors, ics, and central control)
- Pico 7 Controller
Because the remote observing machine is not on the same network as the computers on the mountain, you will not be able to ping any mountain computer with the exception of michelson. Proxy commands have been set up for the mircx, pavo, and pc-ctrlvega machines, so you can ssh into those directly, but for all other computers, you must ssh into michelson first.
The remote desktop program is needed to connect to three different windows machines on the mountain. Because they are all using the default port for remote desktop, we cannot add the appropriate port forwarding to the standard SSH tunnel. You will need to run a custom ssh tunnel just for using remote desktop:
Then, to use remote desktop for these three machines, run
rdesktop -g 1000x1000 localhost:400X where X is 1, 2, or 3 for each of the three machines.
Exiting the VNC viewer
When exiting the VNC viewer, please close all windows and close the VNC viewer by closing it directly or by using the "Exit viewer" command in the F8 context window. DO NOT log out of the vroc account. If the previous user logged out of the vroc account, you will see only a black screen when you connect.
For PIs who cannot make it to the mountain and have arranged for their observations to be taken on the mountain, a lurking mode is available whereby they can watch as their data are taken. Lurking mode is currently available for Classic and CLIMB only.
To use lurking mode, follow the same steps as outlined above. The address and password you are given will connect to a different account on the same remote observing machine which will give you limited functionality, but let you see as your data are taken.
The modified “lurking mode” versions of the control software guis are accessible as desktop buttons. Menu items will be added eventually. These include:
- Lurking Telescopes
- Climb (1 and 2)