Using VNC with the IRTF
VNC stands for Virtual Network Computing - It is software that enables you to have a virtual desktop on a computer (server). This virtual desktop can then be accessed using browser clients or X11 interfaces, giving you access to your virtual session from any location. Visit the VNC home page for more information.
A java-enabled web browser or the vnc client software must be installed on the computer. The vnc client (vncviewer) may be downloaded from the vnc webpage and may be installed on Linux, Unix, and windows computers. A ssh client is also required to create your guest account. There may be a mouse issue with Mac users and VNC. The current fix requires a three-button mouse for the Mac.
As a prerequisite, you should create a guest user account for your run.
Contact the telescope operator at (808)974-4210 (or a member of the IRTF staff) and request that they start a vncserver for you. You will need to provide the guest account name, the instrument you will be using, and your preferred display number, if you have one. The IRTF staff member will start the vncserver for you and once it has been started you may access it using one of the methods listed in 1.4.
Note that any combination and number of viewers may be used to view the session from a vnc server.
For example, one viewer running on a Sun using vncviewer, another win32 viewer running on a pc, and a third viewer using Netscape on a Mac.
Open an xterm on your local computer and start the vnc client. You will be prompted for a password that will be given to you by the telescope operator.
% vncviewer stefan.ifa.hawaii.edu:n
Note: if you are using any of the 24 bit vnc servers, and you still see a non-continuous (only a few gray levels) grayscale in DV, try running your client with the -FullColour or -FullColor options.
Run the client by executing the vnc viewer downloaded from the VNC download page. You will be prompted for a password that will be given to you by the telescope operator.
There are serveral MacOS X vnc viewers available for free download. Here are a couple that have been used successfully for IRTF observations:
Run the client by executing the vnc viewer downloaded. You will be prompted for a password that will be given to you by the telescope operator.
From a java-enabled browser (e.g. Netscape/Firefox/Mozilla or IE explorer) enter the following URL: http://stefan.ifa.hawaii.edu:58n where n is the display number you selected in 1.3, e.g. http://stefan.ifa.hawaii.edu:5801 (n = 01). You can open the same display on any java-enabled browser. You will be prompted for a password that will be given to you by the telescope operator.
Note: if you will be using any of the 24 bit vnc servers (nsfcam2, mirsi, or spex), you will need to run a standalone client. It appears that the vnc java applet used by the browsers (whether on mac, windows, or linux) does not display the grayscale properly. It is restricted to 256 colors (8-bit) and there is no way to change that at this time.
When you are finished using the vnc server, request that the telescope operator (or IRTF staff member) kill the server. You will need to provide the display number and the guest account for which the server was created. Please note that killing the server will disconnect all the client sessions and shut down the server. If you do not explicitly request the telescope operator to do this, it will be done at the end of every night/day anyway, so please make sure you have saved any work you are doing before closing down after your observing slot.
maintained by Miranda Hawarden-Ogata (hawarden@ifa.hawaii.edu)
Last modified July 14, 2008