1. Starting the system
2. LIRIS real time display (RTD)
3. LIRIS mechanisms
4. Focusing
5. LIRIS observing commands
6. End of night
7. Shutting down the system
8. Writing data tapes
9. Important notes
    

1. Starting the system

When you arrive at the telescope the system and the requested instrument will already be setup for you. The software should be running, too. If not, ask your telescope operator (TO) or support astronomer (SA) to do it for you. In the very unlikely case that the system is down and you have to bring it up yourself,

• Log on to the Sun workstation taurus (next to the ICL computer):
  LOGIN: whtobs
  PASSWORD: provided by the TO or the SA
   
  An openwindows session starts, and an xterm pink window (labeled "Central intelligence of observing system") and several xterm orange windows will appear. Also a netscape window appears, which shows the UltraDas Software Operations Manual (command dictionary included).
  Minimise all the orange windows except the one corresponding to the DAS (Data Acquisition System) computer which controls LIRIS (get its name from the white board above the ICL computer). It is entitled DAS at the moment (July 2002).
   
• Start the Data Acquisition System:
  • Type obssys in the DAS (orange) window. It defines the software to use and will then prompt you to select the observing system. Type number "1" for manual instrument selection and select LIRIS and wait until the prompt DAS> appears.
  • To start the software, type
    DAS> startobssys
    Wait for the prompt and minimise this window (it is not needed until you shut down the system).
     
• Start the system computer:
  • Type obssys in the pink window.
  • Enter the same option number as in the orange DAS window and wait to get the prompt SYS>.
  • Type SYS> startobssys
    This initializes the telescope control software (TCS) link as well as the LIRIS controllers, and brings up several new windows:
    • A real time display (RTD) control tool
      
    • An Ximtool to display the data
      
    • The LIRIS mechanism mimic.
      
    • An identification window. Enter your name and proposal identification.
      
    • The observing log.
      The log is automatically updated each time a new file is written to disk. To comment a file click once with the mouse on the file and a box appears where you can type shorts comments.
      
    • The array info display window
      
    • The talker window. It displays messages from the observing system to the user.
       
• If you want, you can bring up a telescope info display window:
  SYS> tcsinfo&
   
• To examine LIRIS data:
  
  • Login at lpss13, dedicated to LIRIS quick look reduction (the monitor right of taurus):
    LOGIN: whtguest
    PASSWORD: provided by your support astronomer.
  • Open an xgterm:
    xgterm -sb&
  • Open an Ximtool:
    ximtool&
  • Start IRAF from the home directory ( /home/whtguest/ ) in the recently opened xgterm:
    cl or ncl
  • Change to the disk and directory where the data is going to be stored, e.g.
    cl> cd /obsdata/whtb/20040501
  • Start the LIRIS quick look reduction package in IRAF:
    cl> liris
     
• Now is a good moment to take two darks of the same exposure time and measure the LIRIS array readout noise:
  • SYS> lblanks     Put blanks in the light path.
  • SYS> dark liris 2 "dark 2s a"     Take the first dark frame.
  • SYS> dark liris 2 "dark 2s b"     Take the second dark frame.
  • On lpss13, within the liris quick look package, type:
    in> ifindron
    and enter the filename of the two darks. The result is given in ADU.
     
  IMPORTANT: the readout noise value given in the image FITS headers is fixed, and regularly updated, but not derived from each specific image. Observers are therefore recommended to check the readout noise of their images.

Next: 2. LIRIS real time display (RTD)