JKT Duty Engineer Checks
For the JKT A&G box (JAG) with SITe2 and UltraDAS

Rev 1.8

Hot Links


  1. First check the Operations Logbook for any restrictions that may be still in force. Turn on the DOME LIGHTS from the console and raise the control room blind.
  2. Make a visual inspection of the observing floor to check that the telescope is free to move. e.g. No ladders or steps are close to the telescope or test instruments connected.
  3. Check to see that the light tight BLACK BAG is fitted around the bottom of the telescope. i.e. Enclosing the JAG and CCD cryostat. If this is not correctly fitted or missing, it can affect the balance of the telescope which may cause tracking errors.

  4. Move the RISING FLOOR down to a safe level that will not endanger the telescope when slewing.
  5. Push the LAMP TEST button on the console. Check that all used indicators are working (e.g. the ALARMS).
  6. Replace any defective lamps with new replacements (28v). There should be a supply of these in the cupboard in the control room.

  7. Rotate the dome manually a small distance in both directions using the DOME +/- buttons. If the weather permits, OPEN and CLOSE the dome SHUTTER a small amount, but see important note below.

    n.b. If these do NOT work from the console, check outside on the observing floor. The switches on the dome supply wall box must be pointing to REMOTE. They may have been switched to LOCAL.


    The tests for opening the shutters only applies if they are working correctly. If any mechanical problems exist then do NOT do these checks. Provisional instructions on how to open/close the dome will have been issued if this is the case.

  9. Switch ON the TELESCOPE POWER using the keyswitch on the top right hand panel of the console.
  10. Push the MIRROR OPEN button. Check the mirror petals open fully then push the MIRROR CLOSE button.


The JKT observing system comprises of three computers. These currently being:

It is best to bring the observing system down and re-start it. This not only generates a new Observing Log for the day, but prevents problems due to possible memory leaks which can build up with time. To shut down, proceed as follows:

    Logging out from the Observing system (ICS) and uDAS Sparcs

  1. On the  jktics/jktdr computer, enter in the pink (CI) window:
  2. SYS> shutdownobssys
    Do you want to wipe out the system Y/N? y
    SYS> exit
  3. In the orange (DAS) window, enter:
  4. SYS> shutdownobssys
    Do you want to wipe out the system Y/N? y
    SYS> exit
  5. If there are any other windows seen, shut them down too. Here is what to type for various prompts:
  6. To shut down IRAF:

    cl> lo
    To exit the observing system:
    jktobs@..... > exit
    Graphics windows without a prompt can be exited as follows:

  7. Click the right mouse button over the background and choose the "exit" option at the bottom of the menu. This will log you right out of windows.
  8. Logging out from the TCS

    The TCS, a DEC ALPHA computer on the ground floor, is run from the X terminal in the console. In the TCS User window, enter:
    USER> tcsexit

  9. Exit any other windows and click on the "cancel" button at the bottom right.
  10. When the only remaining window is the console, click on "console" (at left) and "reboot" (bottom of that menu) and "OK". This will reboot the X terminal.


  1. When the X terminal has rebooted, start a session on  jkttcs (lpas1)
    Username: JKT_LOGIN
    Password: ********* (as shown on monitor)
  2. Start the TCS with:
  3. Option> start
    The User and Infodisplay windows will appear.

  4. Push the Oil Pump RUN button. Wait until the OIL ALARM indicator lamp has gone out.
  5. Zerosetting the telescope

  6. Visually check that the telescope is at, or very near, zenith park. If it is not at zenith park, move it as close as you can using the engineering HA and DEC +/- buttons.
  7. Put the "Rate" control knobs for HA and DEC to about half way.
    n.b. There is NO NEED to set these controls to the green marks. In fact, the telescope can be zeroset at full velocity. This was a 'left over' from days when old filament lamp Baldwin encoders were used that loosed counts at higher speeds.
  8. Using the HA and DEC buttons, move away from zenith park in the -ve direction for about 3 seconds. You can move HA and DEC simultaneously.
  9. In the TCS User window, enter:
    USER> zeroset ha target
    USER> zeroset dec target
  10. Using the HA and DEC buttons, move back towards zenith park in the +ve direction until the TCS beeps and tells you the zeroset is successful. Again, you can move both axes simultaneously.
  11. Testing the telescope in Computer Mode

  12. Put the telescope into computer mode by turning the COMP keyswitch. The green section of the ENG/COMP push button switch should illuminate showing that Computer Mode has been selected.
  13. Check the Local Sidereal Time display. The telescope can be safely moved in RA +/- 3 hours away from the LST as displayed.
  14. Enter a value of RA either +/- 1 hour away from the displayed LST.

    In Dec, a good position for checking the telescope is at the celestial equator. This will position the telescope tube at right angles to the polar axis.

    Format for entering telescope co-ordinates is :

    USER> source name hh mm ss dd mm ss equinox
    name           No more than 20 characters
    hh mm ss       RA       hrs mins secs
    dd mm ss       DEC  +/- degs mins secs
    equinox        Usually J2000
    Example: LST is at 15:30:00
    USER> source TEST 16 30 00 00 00 00 J2000
    USER> n
  15. Check that the telescope gets into "Tracking" mode and the dome moves.

    n.b. It is normal for the dome angle to be different from the telescope azimuth. This is because the telescope tube is not in the centre of the dome.

  16. Put the telescope back to zenith park.
  17. USER> park zen
  18. Send the dome to 235 degrees.
  19. USER> dome 235
    and check that the arrow on the dome rail lines up closely with the mark on the dome. These marks are almost opposite the control desk and can be seen through the window.

    n.b. If there is a significant difference in the position between the marks, it is highly probable that the dome encoder sprocket has jumped the chain! This can cause the dome to vignette the telescope and would need to be fixed urgently. To rectify this, proceed as follows:

  20. Return the telescope back into engineering mode by pressing the ENG/COMP button. Enter "ack" on the keyboard to stop the TCS alarm.
  21. Turn off the telescope power. This will also switch off the oil pump. Push the CANCEL button to mute the alarm. Close the roller blind.


n.b. Always bring up uDAS before starting the ICS. When shutting down, do this in the reverse order.
  1. Log on at the console of the JKT Observing System Sparc :
  2. Username: jktobs
    Password: ****** (as shown on monitor)
    Two xterm windows appear: one with a pink background, logged in to the System computer and one with an orange background logged in (via rlogin) to the DAS computer (located in the control room annex).

  3. In the DAS orange window, enter :
  4. Check the whiteboard for the current observing system option numbers. These are usually :

    Enter these numbers (or what is shown on the whiteboard) for the observing system requirements. A message will then appear asking if you want to start the observing system.

  5. In the same window enter :
    and check the messages for any errors.
  6. Eventually, you should get the prompt :
    If there were no errors, the DAS is now ready.
  7. In the pink window, type :
    Enter the menu option numbers that were used when starting up the DAS. These must be the same.
  8. In the same window, enter :
  9. The Observing System will now be loaded. During this process several windows will be generated. The important ones being:

    Check that you have the prompt:  SYS>

    Check that you can send commands to the TCS from the ICS.

  10. Check you can send commands to the TCS.  e.g.
  11. SYS> tcs page
    The Infodisplay on the Xterm should change. There are three pages available which can be toggled using the PAGE command.

    The Observing System is now ready to rock n'roll !


    Taking a BIAS frame

  1. Make sure the dome lights are out and the control room blind is down.
  2. On the ICS Sparc in the pink window, enter :
  3. SYS> bias
    The uDAS mimic window will show the operations and progress as the CCD is readout, processed and written to disc.

    Displaying the image

    n.b. Optional: To avoid screen congestion, open up a new screen (using the CDE control bar buttons). This keeps the image data reduction packages seperate from the Observing System windows.

  4. Start up IRAF and XIMTOOL using the procedure below :
  5. In the IRAF window, move into the directory where the images are stored. The directory format is: yyyymmdd   e.g.
    cl> cd /obsdata/jktb/20020124
    n.b. The data path to the image files can be found at the bottom of UDAS mimic.

    There are 2 obsdata discs, currently : jkta, jktb. The data will be stored on the disc that has the most space available. A new "date" directory will be automatically created at midday.

    When the bias frame has read out, the computer will beep. Check in the OBSERVING LOG window that the image has been received and that the headers have been written. The images are stored as "rnnnnnn.fit" files, each having a sequential run number.

    e.g.  r123456.fit

  6. In the IRAF window, type:
    cl> display r123456[1] 1 fill+
    Where the run number corresponds to the last image taken. ximtool will now display the image.

    IMPORTANT : You must add the [1] extension (which denotes the window selected) after the run number.
    n.b. This applies to all IRAF commands that you may use.

    n.b. The WINDOW syntax for uDAS is:

    SYS> window 1 "[xtart : xfinish, ystart : yfinish]"

    The fill+ option will make ximtool display the ENTIRE ccd image.

  7. Examining the image

  8. In the IRAF window, enter:
    cl> imexam
  9. Move the mouse into the area of the displayed frame and left click. Move the mouse around the image area, typing: m.  This will produce statistics for a box containing 25 pixels centred on the mouse cursor. Check that the noise(e) levels correspond to the CCD data held in: Ultra SITe2

  10. If there are white spots, move the mouse over them and type: s.  This will produce a surface plot. Check that the white dots are single pixels.
  11. To exit imexam, leave the mouse cursor over the image area and type:  q


n.b. If there are any problems with the JAG, refer to the document: Taming the JAG which should solve most problems.

  1. Move the ccd FILTER WHEEL. (positions are 1 to 6)  e.g.
    SYS> filter 3
    You will see the filter on the JAG mimic turn blue and the position change. n.b. You may also see the autoguider filters and the telescope focus change if a filter of a different thickness is selected.
  2. Test the ccd SHUTTER.
    SYS> shutter open
    Check that the JAG mimic shows the shutter is OPEN. The shutter status will also change colour in the uDAS mimic window. Close the shutter with:
    SYS> shutter shut
  3. Move the AUTOGUIDER probe ready for the autoguider tests.
  4. SYS> autocentre
    You should see the probe X / Y positions on the mimic turn blue and the numbers change. When the probe is at the demanded position, the numbers should be green. There will also be a message on the mimic saying that the probe is close to the BLIND SPOT.

  5. Move the TV acquistion MIRROR into the beam and open the TV SHUTTER.
  6. SYS> tv on
    You should see the TV mirror and shutter turn blue. The TV flat will move IN to the light path and the TV shutter will OPEN. They will turn green again if the operation was successful.


The JKT autoguider uses an image dissecting PMT mounted on an X/Y slide occupying one half of the JAG. The tube can be easily damaged by over illumination and for these reasons, precautions are taken to switch OFF the main dome lights when the autoguider is activated.
  1. Power on the autoguider (the red "ON/OFF" button.). This should also test the over illumination safety interlock and turn off the dome lights.

    Important  Make sure this happens and that there are no other lights on in the dome.

  2. Switch on the autoguider TV monitor (small right hand screen).
  3. In the TCS user window, enter:
    USER> field
    A small window will appear within the main autoguider display. You should see very little or no counts in this window.
  4. Move the autoguider probe from the ICS:
    SYS> autoxy 3000 23000
  5. The probe will now move out of the `blind spot` and pixels at different light levels should be building up in the small autoguider window.

  6. In the TCS user window, enter:
    USER> acquire
    The autoguider screen should say "ACQUIRING" and then "PULLING IN". Check that the autoguider probe X and Y values are changing on the mimic.

    n.b. You won't be able to check the guiding without a real star.

  7. To finish testing, enter:
    USER> agstop
  8. Switch off the autoguider and monitor. The dome lights should come back on.


The JKT uses an intensified Westinghouse TV camera in conjunction with a GRINNELL SYSTEM integrating frame store for image acquisition.

    Testing out the TV camera in direct viewing mode.

  1. Make sure the TV flat is IN and the TV shutter OPEN.
  2. Switch on the Grinnell TV display and the direct viewing mode TV monitor (small left hand screen).
  3. On the TV remote control box. Make sure the GAIN control is backed off (fully anti-clockwise).
  4. Push the ON button on the TV remote control box. This will also TURN OFF the dome lights.

    Important  Check this happens and that there are no other lights on in the dome.

  5. When the red DELAY led goes off, the yellow RESET led should go off also. n.b. If this doesn't happen, check that the GAIN control is turned back past a `click stop` when rotated fully in the anti-clockwise direction.
  6. Push the DIRECT button on the Grinnell control panel.
  7. Slowly increase the GAIN until you see scintillating speckles (ion events) on the direct viewing mode TV monitor. Toggling the H and V scan direction change switches and seeing the `target' moving around the screen is a good test that the TV camera is healthy.
  8. Important   Always return the TV scan switches to their `marked` default positions.

    Checking the GRINNELL system

    This enables an image to be built up within a frame store memory over a series of integrations. Using the GRINNELL, the TV system can resolve much fainter objects than when using the DIRECT viewing mode.

  9. Back off the GAIN control and push the INT (Integration) button.

    n.b. If the TV RESET button has been pushed, the `black level` will default to a value of 2048

  10. Set up the Grinnell TV Integration values as follows:
  11. n.b. The BLACK LEVEL and CONTRAST switches have continuous rotation. Check in the small window in the lower right hand corner of the Grinnell monitor to see the values change.

  12. Watching the direct TV monitor, increase the GAIN slowly. You should see a pulsating patch of light.
  13. Watching the Grinnell monitor, increase the CONTRAST until you see a build up of light somewhat `pixelly` in appearance.
  14. Decrease the GAIN until the light patch disappears.
  15. Push the AVERAGE button.
  16. Slowly increase the GAIN until you see the build up of light again. The light patch will now have a smoother profile.
  17. Turn the GAIN down, push the OFF switch on the TV remote controller and switch off the TV monitors. The dome lights should come back on.
  18. On the ICS, in the pink window enter:
    SYS> tv off
    to move the TV flat out of the light path and to close the TV shutter.


Filling the Cryostat

The CCD should be filled early afternoon. It's best to do this AFTER running the telescope checks as the cryostat can empty out when the telescope slews.


Before leaving the JKT

  1. Replace/zip up the black bag around the JAG.
  2. Lower the rising floor so that the telescope can't hit it.
  3. Back in the control room. Turn OFF the dome lights and ...
    Don't forget to tick off the checks as completed and to sign off in the logbook

Document history

Rev 1.0 First release: Nov 10th 1998 Sheila Crosby
Rev 1.1 Revised and extended: Nov 26th 1998 by John Mills
Rev 1.2 Revised after s/w upgrades: Dec 4th 1998 Sheila Crosby
Rev 1.3 Revised IRAF startup and image file access in the Data Acquisition section: Mar 29th 1999 John Mills
Rev 1.4 Cryostat filling procedure corrected: Apr 21st 1999 John Mills
Rev 1.5 LN2 dewar earthing added. SITe2 noise value added : Oct 5th 2000 John Mills
Rev 1.6 Changes made for UDAS operation: Jan 9th 2002 John Mills
Rev 1.7 Removed machine names. Generic names only now: July 16th 2002 John Mills
Rev 1.8 Wording changed from 'Shutting down' to 'Logging out from' the JKT Observing System : July 16th 2002 John Mills

THIS FILE: http://www.ing.iac.es/~eng/ops/jkt/jkt_checks.html