INT Duty Engineer Checks
IDS with SDSU DAS and TV system
FILL THE CRYOSTAT AFTER DOING THE DE CHECKS else the cryostat can empty out when the
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.
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
Push the LAMP TEST button on the engineering rack. Check that all used
indicators are working (i.e. the ALARM lamps on the console and the push buttons
on the engineering rack). Replace any defective lamps with new replacements (28v).
There should be a supply of these in the cupboard in the control room.
On the engineering rack, test dome rotation manually in both directions by holding
down the DOME + then - button for a few seconds. This tests the integrity of
the engineering TEM-L system.
- If the weather permits, open the dome shutter a small amount.
Use RAISE MICRO (until the OVERTRAVEL indicator goes off) then push RAISE
MAIN. To close the shutter, push LOWER MAIN and when the shutter stops moving
down in fast motion, use LOWER MICRO to fully close the shutter.
n.b. If the dome or shutter does NOT work from the engineering rack push buttons, check the
manual controls on the large grey cabinet mounted on the dome. Access is via the balcony. The
switches (some key operated) associated with the dome and shutters must be pointing to REMOTE.
They may have been switched to LOCAL.
LOGGING OUT FROM THE IDS OBSERVING SYSTEM
It is important to log out and restart the INT observing system and the TCS when
doing the daily checks. This especially applies to the TCS and ICS computers where memory leaks can
cause problems. This should also be done AFTER 12:00 (UT) so as to generate a new night LOG
for the observations.
Observing system computer generic names:
Telescope Control System (TCS)
Instrument Control System (aka The Observing System
Slit viewing (or direct acquisition) TV CCD camera
Data Reduction PC
Associated with these computers there are 4 flat screen monitors. These being (left to right) :
- The TCS and slit-viewing TV camera (1 screen and a keyboard)
- The ICS (Observing System) (2 screens and a keyboard)
- The Data Reduction PC (1 screen and a keyboard)
Logging out from the ICS and DAS
Logging out from the TCS
- In the TCS USER window :
The TCS USER and DISPLAY windows will disappear.
Logging out from the TV system
STARTING UP THE TCS AND TV SYSTEM
NOTE The order of how the observing system is started is important.
The TCS must be started
before the ICS/observing system. Likewise, the DAS systems must be started before the Observing System.
TV start up
- Two Xterm windows appear: One with a white background for the TCS and one orange windows for the TV Data Acquistion System (DAS).
In the organge window type obssys and start the observing system as
When prompted to choose a system, select option 1 (MANUAL CAMERA SELECTION)
The display responds with:
The following cameras/instruments are configured:
AG0 on TESTINSTRUMENT using inttv.
- Select option: 1
- After displaying some more information enter:
- When the prompt returns, enter (with AG0 in UPPER CASE) :
DAS> startag AG0
Select autoguider instrument station
The DS9 display tool, autoguider (TV) control panel and a TALKER window (which can be minimised)
should now appear.
Please choose a station > 4 (CASS TV)
Do you wish to use DISPLAY TOOL (eg DS9)[y/n] y
Logging into the TCS
Check that the User and
Infodisplay windows appear.
STARTING UP THE DAS AND ICS
n.b. Always bring up the DAS before starting the ICS. When shutting down, do this
in the reverse order.
ALL OBSERVING SYSTEMS NOW RUNNING
* The CASS/IDS observing system is now ready to rock 'n' roll *
CHECKING OUT THE TELESCOPE
Start the oil oump
- On the engineering rack, push the Oil Pump RUN button. Wait until the OIL
alarm indicator lamp on the console has gone out.
- Push the red ACCEPT button to mute the audible alarm and push the green
RESET button (if illuminated) to enable the telescope drive power amplifiers.
- Check that the telescope is in ENGINEERING Mode. The yellow section of the
ENG/COMP push button switch should be illuminated. This is the default condition.
Zerosetting the telescope
- Visually check that the telescope is near zenith park. (i.e. vertical). The HA (Hour Angle)
synchro position indicator pointers should be at the "12:00 o`clock" position with the DEC (Declination)
indicator pointers at the "9:45 o'clock" position. If the position indicators are some way off, move
the telescope close to these positions using the HA and DEC +/- buttons on the
engineering rack. Select quick motion (QM) if the telescope is a long way off position then go to slow
motion (SM) to make the final adjustments.
- In the TCS User window, enter:
USER> zeroset ha target
USER> zeroset dec target
- Using the HA and DEC +/- buttons with slow motion (SM) selected and the drive rate
controls adjusted for a very slow speed, move the telescope so that the synchro dial
pointers MOVE THROUGH the "12 o'clock" position in HA and the "9:45 o'clock" position
n.b. The synchro pointers are slightly misaligned and the zerosets will occur a short
distance away from their nominal positions. Markers have been placed against the HA and DEC
synchro dials to where this should happen.
The TCS will beep if the zeroset is successful. The yellow LED's mounted above the synchro
dials will momentarily flash also confirming that the telescope has been zeroset.
Incremental focus position transducer (SONY) check
- In the TCS user window, enter:
USER> page enc
- Check that the Focus Absolute and Incremental transducer values are in close agreement.
If so, enter :
USER> show enc
to see which focus transducer is IN USE. It should be the Incremental. If it is the
Absolute, enter :
USER> enc on foc inc
to switch to the incremental transducer which is more accurate and now used for focus/temp tracking.
n.b. If the transducer values are NOT in close agreement or there is a problem with the Sony unit,
follow the link to:
Sony focus encoder Info or
refer to the appendix pages in the INT DE CHECKS folder.
- To return to the TCS DISPLAY info page :
USER> page info
Testing the telescope in Computer Mode
- Put the telescope into Computer Mode by turning the COMP keyswitch on the console. The green
section of the ENG/COMP push button switch should illuminate showing that Computer Mode has been selected.
n.b. The HA and DEC slow motion (SM) push buttons MUST be set for SM mode i.e. All
the lower green sections of the buttons illuminated) before Computer Mode can be selected. If the yellow
section of a QM button is illuminated, push the adjacent SM button to re-engage the slow motion clamps.
Computer Mode should now be available.
- Check the LOCAL SIDEREAL TIME display. The telescope can be safely moved in RA (Right Ascension)
+/- 3 hours away from the meridian (LST being the local sidereal time on the meridian).
- Enter the RA and DEC coordinates into the TCS. In RA use a value +/- 2 hours away from the LST. In DEC,
a good position is 0 degs (the celestial equator) which will position the tube at 90 degs to the polar axis.
Format for entering telescope co-ordinates is :
USER> source name hh mm ss dd mm ss equinox where:
name No more than 20 characters
hh mm ss RA hrs mins secs
dd mm ss DEC +/- degs mins secs
equinox Usually J2000 or A (apparent)
Example: LST is at 14:30:15
USER> source test 16 30 15 00 00 00 j2000
Will move the telescope 2 hours west from the meridian and put it at the equator. The next
instruction executes the move.
- Check on the TCS INFO display that the telescope gets into Tracking and that the dome moves.
Once settled and tracking, the Position Errors in RA and DEC should be at or very close to zero
n.b. If the dome does NOT move, it may have been overriden? On the console there is a bank of five push
buttons called SELECT MANUAL CONTROLS. Check that the button labelled DOME/SHUTTERS
has not been set. If the dome still doesn't move, check the notes in the PRELIMINARIES section in
Check that you can send commands to the TCS from the ICS.
This checks the communication link between the TCS and ICS computers. Test this by moving the focus.
- Make a note of the telescope focus and send it to a different position. n.b.
The focus for IDS is nominally 15.80 mm.
- In the Observing System window, enter for example :
SYS> focus 15.90
- Check that the focus moves to the demanded position. Return the focus back to where it was before testing.
Finalising the telescope checks
- Put the telescope back to zenith park.
USER> park zen
- Return the telescope back into Engineering Mode:
- Switch OFF the OIL PUMP and push the ACCEPT button on the console to mute the alarm.
CHECKING OUT THE TV SYSTEM
A major upgrade in re-commissioning the IDS. The slit/direct viewing TV acquistion camera now uses a WHT
type TV/AG CCD head with an SDSU controller and replaces the old Westinghouse/Grinnell TV system that was
in use for more than 20 years!
- In the TV control window SDSU AUTOGUIDER ON AG0, check that the Peltier cooler is showing
ok and that a sensible temperature ~ 236 K is displayed. This gives confidence that the system
software is communicating with the SDSU TV controller.
- Position the TV probe for viewing the slit at the rotator centre:
SYS> tvxy 498000 500000
- In the TV-DAS-window on the TCS, define a 3x3 binning of the acquisition camera, which allows fast readout and display cycles. Type the command:
DAS> bin 3 3
- In ds9, you should check that the image has been inverted in the
x-direction (From the top menu choose Zoom then check that the Invert
X option is checked).
A green cross + for the instrument
rotator centre, and a blue cross +
at the slit centre should also be displayed. In case they do not appear, from
the top menu Region you can (Load Regions...) and load the most
recent region file.
If the green and blue crosses disappear after starting acquisition, click on
ds9 top menu File, Preserve During Load, and check the box
- Click the button: TV
The display will show the TV camera integrating and then reading out. The default time is 1 second, but
this can be increased if necessary.
To see the slit of the spectrograph, some light needs to fall into IDS. Partially open the mirror
petals by pushing the PRIMARY MIRROR button for a few seconds on the engineering rack. With the
main dome lights on the slit should be obvious. To change the brilliance/contrast of the image: With the
mouse cursor in the image area, hold down the right button whilst dragging the mouse vertically or
n.b. If the slit still cannot be seen, it may be that the comparison lamp mirror in the A&G box is
in the light path. If so, remove it with the command (from the Observing System window) :
SYS> compmirror out
- Click the button: STOP to halt the continuous readout.
The TV tests are completed
CHECKING OUT THE AUTOGUIDER
The Cass Autoguider consists of an RGO Peltier cooled CCD head fitted onto an X/Y table within the
A&G box. The image processing is done using a VME system located in the CLIP CENTRE. Only limited
testing can be done during the day, but the checks below should be sufficient to see if the autoguider
- Click the FIELD button in the autoguider window and wait for the autoguider
to take an exposure and readout.
Check that there is no bad patterning or streaks on the display.
- Click the TV button. The autoguider should now be updating it's display at
With the dome lights turned on (and then switched off) and the mirror petals still partially
opened from the TV tests, a change should be seen in light intensity on the autoguider image display.
Check that it does.
- Click on STOP to halt the continuous readout.
- Test the autoguider probe X/Y table. From the Observing System window :
This will move the autoguider probe to the centre of the field (~ 500,000 encoder units). A
message will also appear saying that the autoguider is vignetting the field.
- Now move the probe to a valid position e.g.
SYS> autoxy 425000 425000
Check that the probe moves to the demanded position on the mimic and that the vignetting message disappears.
It is very important not to leave the probe in the light path, please check this.
n.b. Sometimes an autoguider probe move will time out. If this happens, resend the commands above.
It 'usually' cures this problem!
The autoguider checks are completed. CLOSE the mirror petals and turn OFF the dome lights
DATA ACQUISTION SYSTEM (DAS) CHECKOUT
When testing out the IDS, the normal checks would be:
- To take a bias frame to ensure that the CCD is healthy and
- To take a test arc lamp spectra.
Taking a BIAS frame
- Make sure the dome lights are out and the control room window blind is down.
- In the Observing System window, enter :
- Whilst the bias frame is reading out, set up the Data Reduction PC to check out the image.
Normally this system is left running, but if there's a problem, its best to re-start it. If the DS9
display tool and the XGterm running IRAF are present, then skip down to : Move to the current
image data directory. If not (or there is a problem), do this :
Restarting the Data Reduction PC
Close down any windows and select the logout option by right clicking the mouse on the
desktop. Don't select the SHUTDOWN option unless absolutely necessary. It takes forever to
re-boot the machine as I discovered recently!
When logged out - To restart :
If not already present, start an XGTERM window by right clicking the mouse on the desktop
and selecting it from the drop down menu.
In the XGterm, start the DS9 image display tool and IRAF (Enhanced Command Language
version). At the prompt :
> ds9 &
Move to the current image data directory
The DAS mimic will show what obsdata
disc is in use. There are two OBSDATA discs :
. The data will be stored on the disc that has the most space available. A
fresh directory is automatically created at midday (UT).
- In the IRAF XGterm window, move into the directory where this nights observations will be stored.
The path is shown below with the current data entered in the format :
yyyymmdd (year, month, day) ; e.g.
ecl> cd /obsdata/intb/20060815
Displaying the bias frame
When the bias frame has read out, the computer will beep. After a minute or so, check in the
window that the image has been received labelled as a bias
that the headers have been written. The images are stored as .fit
files, each having a
sequential run number e.g. r123456.fit
- To display the image frame using the example run number above, go into the IRAF window and type:
ecl> display r123456 1 fill+
Where the run number corresponds to the last image taken. You will see the display tool window fill with
the image frame. n.b. The fill+ option will display the ENTIRE ccd image.
Note In DS9, if the bias frame looks 'flat' or the counts show a value of '0' then enter this:
ecl> display r123456 1 fill+ zs- zr- z1=2200 z2=2300
This rescales the image so that structure (or any low level noise) can be seen.
Examining the image
IDS CHECKOUT - TAKING A TEST ARC LAMP SPECTRA
Setting up the A&G box
Setting up the IDS
Although the IDS has two camera ports (235 or 500), only the 235
is currently being offered. If
at a later date both ports become available, the procedure to change between them can be found at:
Changing between the IDS 235 and
During an IDS run do not change the positions of :
- the colliminator
- the slit width nor
- the grating
- Open the CCD camera port shutter is closed :
SYS> camshut open (if the camera port shutter is CLOSED)
Set up a window
Comments: If it is not the first observer's run do NOT change window size,
if you finally do, save previous values to be set back later
Take an exposure
- This will open the SLIT SHUTTER in the IDS for 10 seconds :
SYS> arc 10
The mimic will show the light path through the spectrograph. After the frame has read out, check the
DAS mimic for the run number. A minute or so after reading out the data, the observing LOG window will
display the run labelled as an arc exposure.
Displaying the image
Using IMEXAM to check the IDS focus
- Bring up imexam, position the mouse cursor over a strong arc line and left click. Use the k key
to fit a vertical gaussian profile through the line. The number at the bottom right of the imexam graphics
window displays the FWHM (Full Width Half Maximum) value.
This value should lie between 1 to 3 for EEV10
Note The FWHM value is variable depending on the line(s) selected. However, if the FWHM values are
considerably greater than these orders, the IDS collimator (or CCD cryostat) may need to be
re-focused. Call the Support Astronomer if this is the case.
- If all looks ok,
move and return the hartman to its position before testing, if no hartman is in just do both in and both out:
SYS> hart 0 0
Comments: This moves the two hartmanns to the desired positions.
It is important that the hartmanns are removed from the beam once focusing
is complete. The mimic will clearly show when a hartmann is still in.
SYS> complamps off
SYS> compmirror out
This completes the IDS and DAS checkout
Filling the Cryostat(s) on the IDS
IMPORTANT The liquid nitrogen dewar must be earthed to prevent static discharge. Clip the dewar
earthing cable onto the grounding point. At Cass focus, a copper strap is provided for this on the
FULLY insert the filler tube into the cryostat.
Note The dewars are now left pressurised. OPEN the BLUE dispensing valve.
Wait until liquid nitrogen is SEEN to be coming out of the cryostat.
CLOSE the DISPENSING valve.
- If the hose is of the metal type it can be removed immediately. If its a silicon rubber tube, wait
a minute or so until it has defrosted and becomes flexible before removing it.
Before leaving the INT
- Back in the control room. Turn OFF the dome lights
- Don't forget to tick off the checks as completed and to sign off in the logbook
HTML version. First issued: Mar 11th 1999 John Mills
Corrections and additions made: Mar 25th 1999 John Mills
Cryostat filling procedure corrected : Apr 21st 1999 John Mills
Modified for UDAS usage, LN2 dewer eartling added : Oct 5th 2000 John Mills
Windowing command format corrected: Mar 15th 2001 John Mills
Minor changes made: Apr 27th 2001 John Mills
INTICS changed to lpss7: Oct 29th 2001 John Mills
Corrections and updates made: Feb 6th 2002 John Mills
Sony Focus encoder info added: May 29th 2002 John Mills
Removed machine names. Generic names only now: July 15th 2002 John Mills
Wording changed from 'Shutting down' to 'Logging out from' the INT Observing System : Sep 12th 2002 John Mills
A complete rewrite covering the new IDS observing and TV system: Aug 2006 John Mills
Updated TCS logon information: Sep 2006 Don Carlos Abrams
Instructed DEs not to change the slit width nor the central wavelength: Jan 2007 Don Carlos Abrams
Starting the new IDS TV camera using inttv1: Dec 2011 Jürg Rey
Position TVXY to required position: Jan 2012 Jürg Rey
TV loggin changed: Feb 2012 Jürg Rey
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