WFI on RSAA 40inch Notes
========================
Version 1 written June 2001
(Last update Jan 2008)
The most recent version of these notes is on my web site
Another version appears on the RSAA site, but that may be older.
Revisions
---------
June 2002
-Major: Updated Dome flats procedure
-Minor: html'ised it a bit
August 2003
-Major: New note on focussing- open shutter early
-Minor: more html'ing
October 2003
-Major: Focussing, no more astigmatism to assist focussing :(
January 2004
-Minor updates
January 2008
-Richard Lane has just observed and sent a few suggestions/updates.
Although the 40in is due to be withdrawn from service soon I've added
his notes at the bottom of this file just in case they come in useful.
Introduction
------------
As a first-time observer at the 40 inch (June 2001) I found there was
virtually no useful documentation, ie. troubleshooting notes. However,
with just a few simple fixes, and some minor changes to the way I used
CICADA, I could have saved about three lost nights. I hope this saves
you similar trouble.
Although I did have first-night training and excellent help from technical
support that doesn't cover a problem that crops up after midnight later
in the run!
I am gradually html'ising these and add updates from time to time. If you have
any suggestions or corrections please feel free to let me know.
These notes have grown out of notes written by Terry Bridges and the
collective experience of myself, Bob & John Shobbrook, John Goodyear,
Winston Campbell, Gary Da Costa, Malcolm Harris and many others.
Things change: new problems appear, old ones get fixed, new fixes are
discovered. So feel free to copy, edit, improve, correct, embelish,
simplify or whatever these notes.
Clear Skies!
Andrew Jacob
*****************************************************************************
CONTENTS
========
1/ BEFORE YOUR RUN...
2/ SOURCES OF INFORMATION
A The "40-Inch & WFI DIY Manual"
B "40 Inch Telescope Observer's Technical Guide"
C http://www.mso.anu.edu.au/observing/40in/DirectIm/40in/
D http://msowww.anu.edu.au/computing/cicada/cicada/
E And the WFI web pages
F Other Hardcopy Manuals in the Control Room
G http://msowww.anu.edu.au/observing/tc_manual/
H Additional Notes for Shobbrooks manual
I The Fault Reporting System and RUST
3/ GENERAL INFORMATION
BASIC DATA
CICADA, GIT & Ximtool
General
GIT (Graphic & Imaging Tool)
Ximtool
Screen Preferences for GIT and Ximtool
Other
COMPUTERS
FOCUSSING
OTHER (Readout speed, CCD temp, filter control, dewar vacuum)
CCD GUIDER SYSTEM
GSFIND
Procedure
Restarting Guider PC
TELESCOPE & DOME
Telescope
SDSU Cooling
CAMERA SHUTTER
Priming the shutter
Shutter Priming Delay
IRAF
4/ TROUBLESHOOTING
In the control Room
In the Dome
5/ RICHARD'S UPDATE of Jan 2008
***************************************************************************
1/ BEFORE YOUR RUN...
Before your run I recommend you read:-
a) The "40-Inch & WFI DIY Manual".
[hardcopy only: email John Shobbrook ]
b) A short user's guide...(April 1999)
c) Cicada User's Manual
d) These notes
***************************************************************************
2/ SOURCES OF INFORMATION
There are many sources of information, some more useful than others (from
an observers point-of-view). Not all of it is on the web.
A) The "40-Inch & WFI DIY Manual"
Contents self-explanatory. Essential reading for first-time observers
using WFI at the 40inch.
Get your hands on a copy of this. Written by John & Bob Shobbrook.
This manual is not on the web. Would someone please put it there?
Email John Shobbrook for a copy.
This manual has sections:
Running CICADA
Telescope Setup
Filling the Dewars
Bias Frames
Flat Fields
Dark Frames
Pointing The Telescope - Calibrating the Pointing
Focusing the Telescope
Autoguiding
Data taking
Data Archiving
Shutdown
Accessing the MSSSO Online Comment File
Autoguider Settings
Initialising CCD Hardware
Shutter Priming
WFI - General
B) "40 Inch Telescope Observer's Technical Guide"
A new (June 2001) compendium of useful information and fixes.
More essential reading. You are encouraged to add to this guide to asssist
future observers.
Located on the control room bookshelf.
C) A short user's guide...(April 1999)
Although old this contains some basic 40" observing info. In particular,
a list of what to check when you arrive at the telescope.
D) The Cicada User's Manual
E) The WFI web page at AAO (contains QE curves for the CCDs)
The WFI web page at RSAA
F) Other Hardcopy Manuals in the Control Room
"CICADA User's Manual" - white folder on 40" control-room bookshelf
Probably the same as the Cicada web pages, but best to use D above.
"40 inch Telescope ETS - A Short Users Manual" - located as above.
A useful guide to operating the ETS.
Only exists in hardcopy.
"A Short User's Guide to the 40-Inch and its CCD Camera System"
An old manual. Not entirely relevant to WFI but still useful in parts.
Now contained in the "40 Inch Telescope Observer's Technical Guide" folder
G) The Telescope Command Reference Manual
More technical than the average user needs.
Use the "40 inch Telescope ETS - A Short Users Manual" instead (see F).
H) Additional Notes for Shobbrooks manual
Some additional or alternative notes to add to the Shobbrook manual.
Running CICADA:
-See additioinal notes below
Filling the dewars:
-Press the big red STOP button on the dome console to prevent
errant telescope movement.
-Remove (or replace) the lens-cap BEFORE filling the dewar to avoid (minor)
LN2 spillage from the camera dewar.
-If pressure in small tank seems low, ie. if filling takes ages you can
pressurise the tank by attaching the compressed nitrogen (gas) line. This line is the
spiral orange tube hanging beside the telescope pedastal. Disconnect it from
the 'handgun', and plug into the second outlet on the small bottle. Open the
valve at this inlet, then fill dewar as usual. When dewar is full close both
valves and simply pull out the air line.
-Need a step by step procedure for refilling small LN2 tank from large
LN2 tank??
Flat fields:
Dome flats
-Do these BEFORE filling the dewar to prevent major LN2 spillage.
-Dome at azimuth=~70deg. Telescope at ZD=~70deg gets flat screen in place.
-Use dome lights (tungstens only!) or sunlight by slightly opening the
upper shutter (but sunlight level will vary).
Or use desk lamp on tape-markers in front of console with tel at
RA=ST+12, dec=-85 and pointing at lower shutter, texp=10s.
-Dome flats are not good. Use twilight and dark sky flats. [Terry Bridges]
Focusing the Telescope
-See additional notes below
Autoguiding
-If the autoguider PC has to be restarted:
-When asked for a password, just click "cancel".
-After windows starts open "vncviewer for WFI guider" icon.
The "VNC server" is m40slave:0 . Password is in the back of the
40" CCD Temp Log Book. You will need to scroll down the "Maxim Dl"
window to access the "Guide CCDs - WFI" chooser.
Data archiving
-the DDS3 DAT drive is now on monsoon (since Nov 2000).
-mt rewoffl rewinds and ejects the tape
-How to skip over a tape file if you want to read or extract the
second, etc file??
Shutdown
-Press the big red STOP button when not using the telescope to prevent
errant telescope movement.
Initialising CCD Hardware
-this should be done as a last resort, though there is some disagreement
on this. I've never found it to cause trouble and it does fix several problems!
Shutter priming
-See additional notes below
I) The Fault Reporting System and RUST
Look up Observing & Fault Reports on the RSAA Observing pages.
I found this a bit cumbersome at first, although when you get used to it,
and use the correct search string, this is an excellent way of finding out how
to fix problems (if they have happened before).
****************************************************************************
3/ GENERAL INFORMATION
Some useful information, most of which doesn't seem to appear together elsewhere.
BASIC DATA
==========
WFI chips:
Eight 2k x 4k (2048x4096) CCDs in a 2x4 mosaic.
Each sees 13'x26' (arcmin) making a 52'x52' field.
Pixels are 15micron giving 0.375"/pix (on the 40in at f/8)
Gaps between CCDs are ~20-30arcsec.
Gains are ~1.5-2.1 electron/ADU
Full well capacities range from 81k to 101k e- depending on the chip
RONs are ~3.5-5.5 electrons
(To get Gain & RON follow Gary da Costa's 'Checkstat' procedure in the
"40 Inch Telescope Observer's Technical Guide" or look at the AAO WFI pages )
The awesome SDSU controllers read out the entire array in 55 seconds!!
A full array image is 140Mb in size.
One CCD is 17.5Mb
The /data/monsoon1 disc on Monsoon holds almost 100Gb
(About 4-8 days data for time-series photometry)
A DDS3 125m tape holds fractionally over 18Gb compressed
(ie using allocate mt1)
Writing to tape takes ~11.5min/Gb (~3.5hrs per full tape).
So don't get caught out on your last night, save early!
See also the AAO and RSAA WFI pages.
CICADA, GIT & Ximtool
=====================
General
-------
Strategies to deal with CICADA.
Cicada has a tendency to hang, usually during readout, and sometimes
for no obvious reason (even if you are doing none of the bad things listed
below).
The only remedy is to restart it. To do this:
- In the Observers Window menu select actions|quit_observing_window
- In the CICADA menu select Start_Observing|Exit_CICADA
- From the command line do:
- ps -a |grep cicada
- Look for cicada processes. Ignore *_svc. Kill others with
cicada_cleanup -p 0
cicada_cleanup -p 1
cicada_cleanup -p 2
cicada_cleanup -p 3
- Restart using "cicada &"
In general restarting solves Cicada problems, but it's a pain so...
Follow these next practices for relatively trouble-free operation:-
Pause - DON'T use 'pause'. You may need to logout of the workstation
to restart!
NumLock - Keep NumLock untoggled. It interferes with ximtool (and GIT?)
operation. In particular, it prevents you using right-mouse
scrolling to change brightness/contrast, and inactivates the
ximtool menus.
Initialise Hardware - Some advise this as a last resort only, others
recommend regular use. I haven't had any trouble with it.
And avoid:
-Using ABORT. You'll often then need to exit cicada and restart.
-doing too much (processor or memory intensive stuff) on monsoon during
readout. In particular, avoid:
-Beginning or ending a tar command during readout (during exposing is OK)
-Doing much in Netscape (on-line banking is bad!)
-Copying images (and other operations) in iraf
[You could do these things from murky (or musty?) but its way slower]
-leaving the little GIT "graphics keystrokes" window open during readout
-changing regions (in regions window) during readout [This may not be true?]
During readout you CAN do these:
-change filter, change exposures, change duration
GIT (Graphic & Imaging Tool)
----------------------------
GIT (presently) has a problem with displaying mosaiced images. It displays
them OK on readout but it cannot set sensible scaling parameters to allow
you to calculate star profiles, get single line plots, etc. The ximtool
window just goes all black or white and displays a single value.
To overcome this limitation do the following:
-untoggle NumLock
-select options|start_private_ximtool
-select options|preferences :
-select category "General"
-untoggle "Mosaic MEF files in Cicada mode"
-enter the "MEF extension list", ie a list of which CCDs you want available
for loading into the private ximtool.
Note that if you are only using CCD numbers 1,2,7,8 (say) their MEF image
extension numbers will be 1,2,3,4. ie CCD number and extension number are
different things.
-set "Maximum Cicada images" if necessary
-The list of extensions you have requested will appear in the "image list"
window. Click one and it loads into the private ximtool.
Now you can get star profiles, cross sections, stats, etc. But when the next
image is read out it will automatically be loaded into the private ximtool.
But avoid leaving the little "graphics keystrokes" window open during readout
or GIT will crash out.
Ximtool
-------
North is right, East down.
1 pixel = 0.375arcsec
To move a star N dec offset on ETS is -ve
To " S dec " +ve
To " W RA " +ve
To " E RA " -ve
(This is better seen with a diagram)
Screen Preferences for GIT and Ximtool
--------------------------------------
Select the monitor for these in options|preferences|general
Common practice puts GIT and Ximtool on screen 1.
Other
-----
Binning
If you change the binning, it may not change back again when you reset
it to 1 x 1, even though the regions window shows it as 1 x 1.
Watch the file sizes: should be 271440 blocks (full 8xCCDs?)
Bleeding
Charge bleeding is usually due to too long an exposure time, of course, but...
If readout shows bleeding on brighter stars on some CCDs and bias changes,
restart cicada.
Wrong Frame Size
If there is an error message about ximtool having the wrong frame size,
check that there is not an old cicada ximtool process running:
ps -ef | grep cicada will show it
Many Red Error Windows
If lots of red error windows appear from cicada, and restarting impossible
or doesn't work, try logging out (and back in). That can fix it. If the
error messages involve SDSU, then probably need hardware init (from action
menu): if such error message reported when cicada is restarted, may need
two hwinits. Do the hwinit right after restarting cicada.
COMPUTERS
=========
mosaic (in rack) runs controllers
monsoon (on desk) does the rest - cicada
musty (in office) is a bit slow.
Data is stored on monsoon in /data/monsoon1/cicada/username
FOCUSSING
=========
This is difficult to maintain. There is backlash in the mechanism. And it's
pretty temperamental. But then just wait till you're 38 years old!
Aug 2003: It may pay to open the dome 2hrs before observing (even if this
means before sunset) to equalise the temperature. This has been found to
reduce the dome seeing and making initial focussing each night easier.
This might be seasonal.
(Laszlo Kiss & Peter Szekely)
I found the best method was:
1/ At the beginning of a run (or if focus is lost completely)
Use Cicada's semi-automatic routine under actions|do_focus_sequence...
Follow the prompts and/or read the Cicada manual.
Move the focus by 0.03-0.05 units between each image, starting at
about 31.70. When do_focus_sequence is done set the focus position
with the bottons on the round control paddle
2/ From now on use the telescope's astigmatism. Star images are elongated:
NW-SE => focus too high: Press out [display decreases]
NE-SW => " too low : " in [ ' ' increases]
**NOTE: Oct 8, 2003. The primary was cleaned today and the astigmatism has
almost been eliminated. Damn!
However, you can look at the profile in iraf and still see the effect.
3/ Check star profiles too as you go. Out of focus => lots of scatter
in the profile, of course.
...but then I was only taking short exposures (1-3 mins). Maybe you could
use the autoguider image to maintain focus with long exposures? See also the
Shobbrook manual.
It takes a couple of nights to get the hang of focusing. Be patient!
Approach a focus position from the same direction to remove backlash. Otherwise
you get double and/or smeared images.
Typical focus values range from 31.65 - 31.88
OTHER
=====
Readout speed
Use fast readout for broadband imaging when there is a choice.
CCD temperature
This appears on the Cicada observers window
(from 158-165K for TB). Was ~183.0 for my run.
Filter control
Select instrument_control|Filter:F_40 to open the filter control
window. To initialise, hit "get filter position"
Dewar vacuum
Watch the vacuum gauge - rises about 1E-07 per day.
Probably OK up to about 1E-04. LN2 hold time is about 12 hours.
If much less, dewar needs pumping (can be done cold in daytime).[TB]
CCD GUIDER SYSTEM
=================
I had no trouble with autoguiding, just used all the settings that were there.
The following are Terry's notes. [AJ]
To disable completely, turn off the switch near the mains plug boards
on the north side of guider box, low (on telescope)
GSFIND
------
This shows outline of the main and guiding CCDs relative to GSC
stars. Can start from cicada|tools menu or directly from command line.
Then drag to enlarge the window.
Choose monitor from cicada|options|preferences|general. Display on
monitor 0 to see a green outline against a black background. On
monitor 1 the outline and the sky are black [OK for me on monitor 1, AJ].
Put in the field coordinates and magnitude limits for stars (< 12 for 5 sec
exposures).
Set position angle = 90.
Move CCD outline with the LMB - gives (RA, dec) coordinates of the detector
center.
Put cursor on star and hit spacebar to see the star highlighted in table.
Also gives (x,y) position of selected star in the focal plane.
Procedure
---------
[needs editing? go ahead...]
-Select a guide star and the guide CCD.
-Set telescope, *open shutter*.
-Now go to the autoguider console.
VNCviewer is the guider program to choose from desktop. Maxim is the
autoguider program itself, similar to the one on the DBS.
-Choose "Guide CCDs - WFI" from the menu bar at the bottom of the
window. Choose which guide CCD you are using: same orientation as in GSFIND.
-In the "Maxim CCD" indow click the guide tab, enter the exposure time and
declination.
-Take an exposure with guide CCD: Click "expose" then "start".
-Wait for exposure to read out in big window.
-Move the star where you want it in the guide CCD field:
Use telescope offsets on round "box" to offset telescope;
North pulls the star *down* on guide window,
East pulls the star *right*. ie N is up, E left.
-When star is centered (or where you want it), left-click on it, then
click on Track, then click Start.
-After it reads out it will create a little box in the upper left-hand
corner where you should see the star centered (roughly).
-Wait a bit to make sure telescope is tracking OK (no huge jumps in
star in guide window).
-When telescope tracking ok, close shutter and start the real
exposure.
**If you don't see any star in guide window, make sure shutter open!!**
Restarting Guider PC
--------------------
The Autoguider PC will ask for a password, just click "cancel".
-After windows starts open "vncviewer for WFI guider" icon.
The "VNC server" is m40slave:0 . Password is in the back of the
40in CCD Temp Log Book. You will need to scroll down the "m40slave"
window to access the "Guide CCDs - WFI" chooser.
Hit VNCviewer - this downloads display from m40slave (= m40spare).
Should see icons for WFI GS selector and Maxim. Run Maxim. Get the main
gui up by hitting the CCD control toggle button on the upper
menu bar. Go to setup/restart (don't worry about the "controller
off" message). Need to scroll window up and down to access the
bars at the top and bottom. Don't forget to put in the dec in the
main gui.
Settings for guider: make sure x,y axes enabled. Aggressiveness 4
is OK. X speed 10, Y speed 4.83, x axis cal time 1, y axis cal time 3.
On the guider display: all RA, dec buttons push the image.
TELESCOPE & DOME
================
**Red Emergency STOP buttons**
One is on dome console
One is on electronics rack in control room
Typically, you will run the telescope from the control room while observing
and from the dome when starting-up/closing-down, setting up for dome-flats,
filling dewar, showing-off to visitors, etc.
To transfer control TO dome:
1/ On ETS PC select Configuration|configure. Toggle Dome Control to manual.
2/ Go to dome.
3/ On dome console: switch to slew/set
4/ Move telescope, dome and floor as necessary
5/ Hit big red STOP button if filling dewar or stopping observing.
To transfer control TO control-room:
1/ Hit "emergency-stop reset" button (illuminated beside STOP button)
2/ Ensure floor is fully down
3/ Switch to auto
4/ Go to control room
5/ On ETS PC select Configuration|configure. Toggle Dome Control to automatic.
Telescope
---------
Tracking: Telescope RA tracking sometimes drops out. Just redo the tracking command
to restart.
ETS time: Set the ETS time from the time on the Sun workstation. The telephone time
(1194) may no longer be accurate (see http://tufi.alphalink.com.au/time/time_telephone.html)
The error in the 'phone time won't affect pointing with such large fields but it will affect
your image header times.
SDSU Cooling
------------
The SDSU controllers are cooled by the NESLAB cooler (downstairs in corridor
through library on the left)
If controllers get hot (rare), probably means NESLAB has failed.
Check temperature of controller heat sinks occasionally - touch them.
CAMERA SHUTTER
==============
The shutter return springs were replaced in 2003 but the following problem
still occurs.
The shutter is badly designed. At large easterly hour-angles (>~4hrs) it
fails to reset. Recognise this by the star trails on an
image (trails on CCDs 1-4 trail up, on CCDs 5-8 trail down). There will be
a ramp in the signal across the CCDs too. [need an example image here]
To fix, you will need to prime the shutter manually.
You can listen to the shutter operation (loud CL-LICK on open and close)
with control room door open. A failed shutter sounds different, a woosy,
fainter click. You'll just have to listen! [need an example sound file here]
Priming the shutter
-------------------
Transfer control to the dome.
Move telescope to ~-45deg dec, HA=2.5hrs East. Move floor up to the level
of step 5 on the concrete stairs. This gives access to the big electronics
rack on the side of the telescope tube.
Follow the procedure in the "Observers Technical Guide" and/or Shobbrooks
procedure.
But then test the shutter is working again:
-return prime switch to NOR
-toggle mode switch to manual
-toggle display switch on
-toggle shutter switch open and closed to test.
(Don't forget to wait 8 seconds for the shutter to reset after closing)
-Return all four switches UP before resuming observing.
Shutter Priming Delay
---------------------
The shutter takes a few seconds to prime, so need to **wait** 8-10 seconds
after closing the shutter (eg after acquiring guide star) before exposing.
So a rapid sequence of exposures is out of the question.
IRAF
====
WFI produces mosaiced images. In iraf need to specify the extension number in
the filename, as below.
Hopefully you've used IRAF before!
If not see the MSSSO IRAF User Notes
Set the terminal type as xgterm (at the prompt after mkiraf)
and edit login.cl (or loginuser.cl) to set
set stdimage = imt4096
set imtype = "fits"
Then:
ximtool & :brings up an ximtool to display images in.
cl :starts iraf
And:
display filename[#CCD] 1
imcopy filename[#CCD][xmin:xmax,ymin:ymax] outfile.fits
imexamine filename[#CCD][xmin:xmax,ymin:ymax]
image operations: v does plot from two cursor input positions
r gives radial profile of star, fwhm etc
a gives mag and fwhm etc for star, no plot
Even for a single CCD readout or a small region readout, need
the extension filename[1]
Use the mscred package in iraf to reduce mosaiced images.
ds9, saotng are nice alternative display tools. ds9 can handle
mosaics.
*****************************************************************************
4/ TROUBLESHOOTING
==================
If stuff goes wrong...
Here are some possible causes. Solutions are in these notes or somewhere
in the sources listed above. Sorry, I didn't have time to finish this quite
the way I would have liked. But I'm sure you'll manage :)
First, follow the suggestions above to keep Cicada as stable as possible.
In control Room
---------------
My object doesn't appear on Ximtool after readout?
-Cloud
-Dome is blocking view
-Dome shutter blocking view
-Camera shutter failure
I see streaks on my image?
-Camera shutter failure
-Initialise hardware (a last resort maybe)
I can't analyse images (star profiles, stats, etc) in ximtool.
The image just goes to a single value!
-start a private ximtool in GIT.
Cicada has hung?
-Exit Cicada, cleanup, restart Cicada.
-Stop processor/memory intensive processes
-Avoid using abort
-Don't use pause
Lots of Red Error Windows, Can't Stop Them!
-Kill Cicada from the command line, cleanup and restart
I can't point the telescope more accurately than 20arcsec?
-Tough! The telescope only points to within about 20arcsec
-But, use buttons on round focus/guide/set paddle. Use set or guide speeds.
With practice this becomes fairly accurate (to within a few pixels).
Ximtool menus are inactive
-untoggle NumLock
I can't change brightness/contrast using left mouse scrolling?
-untoggle NumLock
New images keep loading into my private Ximtool?
-turn off automatic loading of images by toggling the "cicada mode"
button under the GIT options|preferences|general menu.
(This is suposed to work, but doesn't)
My star images are elliptical
-focus telescope
Focussing is difficult
-too bad!
-try focusing from same direction to take up backlash
There is bleeding on stars & bias has changed
-restart cicada.
I can't see my guide star (while setting up guiding)
-Open the shutter!
I can't find the "Guide CCDs - WFI" chooser window
-scroll down in the m40slave window
Autoguiding doesn't seem to be working accurately
-set the declination correctly on the "guide" tab in the Maxim CCD window
In Dome
-------
Dome doesn't follow telescope?
-Check dome position encoder (high on the western wall) is flashing its
green LEDs at you. If not restart ETS (select file|shutdown, then startup
at the prompt).
-Put dome in auto mode on ETS (select configuration|configure)
Telescope pointing is bad
-Calibrate the pointing
-Reset the time
Telescope doesn't move
-ensure floor is fully down
-Fault in ETS (Call technical support?)
Telescope moves unexpectedly by itself
-Press big red STOP button on dome console, or on electronics rack in
control room
Shutters don't move
-press shutter|stop button and try again (Listen for the relays clicking
downstairs)
-If upper shutter doesn't close it needs to be driven fully open (onto its
springs) first.
LN2 leaking from filling tube?
-Tighten the various nuts on the tube
LN2 leaking from camera dewar at high ZD angles?
-Remove lens-cap before filling camera dewar
-do dome-flats before filling camera dewar
LN2 small tank pressure low?
-small tank needs filling from large tank (call technical support?)
-pressurise small tank with N2 gas line.
SDSU controllers feel hot
-Water cooler has failed. Check it and restart it, if necessary.
Dewar vacuum rising or focal plane temperature not holding
-pump dewar (call technical support for this)
5/ TROUBLESHOOTING
5/ RICHARD'S UPDATE
===================
Richard Lane observed in early 2008 using WFI. Although the 40in is due
to be withdrawn from service soon I've added the notes he sent me 'just
in case' you find them useful. Thank you Richard :)
WFI Camera Orientation
The camera faces E-W and this cannot be changed to suit other
position angles.
WFI Vacuum
The vacuum reading is mentioned in the notes as something like "this
can be read from the WFI" but there is no explanation as to where this
actually is. Now I know that it's the little box on the side of the
camera/dewar and that it needs to be turned to "on" to get a reading!
No chip #7
Chip 7 is out of commission on WFI (and this is not going to be fixed).
Focussing
The focussing method within CICADA is absolutely rubbish!! When it is
done this way, it works about 1/3 of the time. Whether it does or not
seems to depend on how many different focussing positions you choose for
the focus sequence, although I'm not quite sure about this, it's a pain.
One other thing that makes it such a pain is that once the focus
sequence is complete, one must restart ximtool because it seems to be
impossible to get ximtool to redisplay the full image again.
Having said that, I think I just realised a way to make it do
that. You can probably go into the CICADA settings and tell it to use
the whole chip again, I didn't think about that at the time though
and I'd like to try it to see if it works. I ended up giving up on
this method and did my own focus sequence observations which I
displayed with IRAF and used these for my focussing which I found
MUCH easier and MUCH less frustrating!
SSO 'Rules for Observers'
There is no mention (that I recall) of the the "SSO Rules For
Observers" in the notes. The Rules are on the corkboard in the control
room and really should be read by all first time observers. The thing
that I'm glad I read was the bit about not opening the dome when the
wind is above 45 knots and I think it would be good to point people to
read these Rules. Also the fact that the 'scope shakes enough to affect
observing (blurred images etc) with winds >~35 knots (even with the
lower "wind break" shutter closed) would be worth noting
XIMTOOL issues
There is a mention in the notes of ximtool displaying the current
image poorly and the solution is to reload CICADA/ximtool. This does NOT
fix the problem. I have no idea why ximtool should be so crap at
displaying the current image being read out but it is just appalling..
It overlaps bits and shows mutiple images of objects and other random
wierd effects that have nothing to do with the actual image recorded (if
you open the image in say ds9 they are fine). This makes checking
against finder charts impossible for almost all exposures.
CICADA comment issue [This is a new one! AJ]
CICADA also ransomly [interesting typo Richard:)] decides to
reinclude old comments from other frames in the "object" and
"comments" boxes, i.e. comments that have been deleted from previous
frames suddenly reappear in the current frame for no apparent
reason. This means of course that many of the images I took have
incorrect comments in the FITS header
Dewar Filling Time
The dewar occasionally takes a long time to fill (>=30 mins). If this
happens it is easy to fix, just remove the gun from the air gun gas
line (which hangs from the East side of the mount) and attach this to
the "vent" side of the LN2 bottle/tank/thing to pressurise it (it might
also be necessary to turn up the flow of gas through this line which is
done by turning up the little white tap that is located near the hole
that the gas line enters the mount, although this must be turned down
again so that the white ball in the pressure meter is *just* visible
before reattaching the gun nozzle). This increases the flow of LN2 into
the dewar and reduces filling time considerably.
And a wish list...
Seeing Estimates
Some explanation of easy ways to get seeing estimates would be nice
to have in there (e.g. using IRAF's imexam), although this might be a
little too well known to bother including