INT Duty Engineer Checks
CASSEGRAIN FOCUS
IDS with SDSU DAS and TV system
Rev 3.6
Contents
PRELIMINARIES
FILL THE CRYOSTAT AFTER DOING THE DE CHECKS else
the cryostat can empty out when the telescope slews.
- 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 instruments
connected.
- 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
Note
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:
inttcs Telescope Control System
(TCS)
intics Instrument Control System
(aka
The Observing System) (ICS)
inttv Slit viewing (or direct
acquisition) TV CCD camera
intdrpc 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 :
USER> tcsexit
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 follows:
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:
DAS> startobssys
- When the prompt returns, enter (with AG0 in UPPER CASE) :
DAS> startag AG0
Response is:
Select autoguider instrument station
Please choose a station > 4 (CASS TV)
Do you wish to use DISPLAY TOOL (eg DS9)[y/n] y
The DS9 display tool, autoguider (TV) control panel and a
TALKER window (which can be minimised) should now appear.
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 in DEC.
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.
Check the mirror support
- Uncover the LEDs of the mirror support. They are on the
underside of the mirror cell.
- The green LED should be lit and steady for all three
sectors.
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
USER> n
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 these
instructions.
Check the mirror support
- While the telescopes is slewing, the red mirror support LEDs
will light.
- Once the telescope is tracking, the mirror support will
stabilise, and the green LED should be lit continuously for
each mirror sector.
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:
USER> eng
- Switch OFF the OIL PUMP and push the ACCEPT
button on the console to mute the alarm.
- Cover the mirror support LEDs.
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 Regions.
- 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
horizontally.
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 is working.
- 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 regular intervals.
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 :
SYS> autocentre
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 :
SYS> bias
- 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 :
Username: intguest
Password: ********
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 &
> ecl
Move to the current image data directory
The DAS mimic will show what
obsdata disc is in use. There
are two OBSDATA discs :
inta and
intb. 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 observing
LOG window that the
image has been received labelled as a
bias exposure and
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] 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] 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
Note
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 500 cameras
Important
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
FINALLY...
Filling the Cryostat(s) on the IDS
Procedure
- 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 mirror cell.
- 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
Document History
Rev 1.0 HTML version. First issued: Mar 11th 1999
John
Mills
Rev 1.1 Corrections and additions made: Mar 25th
1999
John Mills
Rev 1.2 Cryostat filling procedure corrected : Apr 21st
1999
John Mills
Rev 1.3 Modified for UDAS usage, LN2 dewer eartling added
: Oct 5th 2000
John Mills
Rev 1.4 Windowing command format corrected: Mar 15th
2001
John Mills
Rev 1.5 Minor changes made: Apr 27th 2001
John
Mills
Rev 1.6 INTICS changed to lpss7: Oct 29th 2001
John
Mills
Rev 1.7 Corrections and updates made: Feb 6th 2002
John Mills
Rev 1.8 Sony Focus encoder info added: May 29th
2002
John Mills
Rev 1.9 Removed machine names. Generic names only now:
July 15th 2002
John Mills
Rev 2.0 Wording changed from 'Shutting down' to 'Logging
out from' the INT Observing System : Sep 12th 2002
John
Mills
Rev 3.0 A complete rewrite covering the new IDS observing
and TV system: Aug 2006
John Mills
Rev 3.1 Updated TCS logon information: Sep 2006 Don
Carlos Abrams
Rev 3.2 Instructed DEs not to change the slit width nor
the central wavelength: Jan 2007 Don Carlos Abrams
Rev 3.3 Starting the new IDS TV camera using inttv1: Dec
2011 Jürg Rey
Rev 3.4 Position TVXY to required position: Jan 2012
Jürg Rey
Rev 3.5 TV loggin changed: Feb 2012 Jürg Rey
Rev 3.6 Mirror support check: Aug 2022 Frank Gribbin
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