If the TCS PC is alive and responding but the programme is not running, it can be started by double-clicking on the TCS icon on the desktop and entering the password in the pop-up box (consult local technical staff for the password). You should then follow steps 1 and 2 in Section~\ref{sec-tcsnormalstart}.
=== If the TCS PC is switched off or not responding ===
Please call the duty electronics technician using the phone number displayed in the warm room.
== Instrument start-up procedure ==
=== STE3/STE4 ===
# Follow the start-up procedure described in Sections 1 and 2 of the "SAAO~CCD Camera Control Program, version 1.2", by J. W. Menzies, available in the warm room and on this page: [[http://www.saao.ac.za/observing/operating-manuals/]]
'''Important:''' Ensure that the following are correct in the blue "Details of Run" startup panel:
* '''CCD''': select STE3 or STE4
* '''Wheel A & B''': enter "1" into both boxes to enable filter wheels
* '''Next file''' number: if this is incorrect, existing images could be overwritten
# Initialise the filter wheels, move to the desired filter and adjust the prebin or window setting, if required.
# Take a bias frame (run a single line module with Repeats=1, Image Type=Bias and Save=Yes) and '''check that it saves to
/data/40in/imag40/YYYY/MMDD on ltsp.
(Note: The data is initially written to the local disk on imag40 (/data/ccd/image/xyx). An rsync job runs on asuthastro every 15 seconds which moves the data onto the SAN. This is accessible from the thin client, logged in as ccd40 in /data/40in/imag40/YYYY/MMDD.
== Observing recipes: sky flats & dome flats ==
=== Sky flats ===
If sky conditions are photometric during morning/evening twilight, you will be able to take sky flats. See Section~\ref{sec-domeflats} if you need dome flats. Sky flats can be obtained in the following way:
# Follow the '''facility start-up''' procedure in Section~\ref{sec-facstartup}.
# Follow the appropriate '''instrument setup''' procedure (Section~\ref{sec-inststartup}).
# '''Slew the telescope to the zenith''', with the open dome shutter facing in the opposite direction to the rising/setting sun. Leave the drives in FAST mode (i.e. not tracking).
# On the TCS, move the '''guide mirror out of beam'''.
# On the instrument PC, '''select the required filter'''. If you need flats in a variety of filters, be sure to cycle through them in the correct order (e.g. UBVRI during evening twilight; IRVBU in the morning). This also applies if you need a range of prebin settings (i.e. start with low binning in the evening; high to low binning in the morning).
# '''With STE3/STE4''', click "Expose", create a module, select "Flat" for the image type, and "Sky" from the pulldown menu beside it. Keep the count rates between 20000 and 50000. Remember to select "Yes" under "Save to Disk". Snapshots can be used to gauge integration times and can be saved to disk if appropriate. Section~\ref{sec-SAAOskyflats} gives a recipe for taking sky flats. See Section~4 of "SAAO~CCD Camera Control Program, version 1.2", by J. W. Menzies, for more detailed instructions on setting up a module.
# Take a '''minimum of 15 flats in each filter/prebin setting''', keeping exposure times ≥1s with STE3/4 to allow the shutter time to open and close (SHOC has no shutter so does not have this limitation).
==== Sky flat recipe for the STE3/STE4: Modules ====
Since all exposures with the SAAO~CCD must be performed via a module (except for snapshots), it may seem challenging to set up and edit modules quickly enough to obtain sufficient sky flats during twilight. However, you can do this pretty quickly using the following example:
# '''Before twilight''', set up a module for your first filter and an exposure time of 1s (do not go below 1~s), with 1 repeat.
# For evening twilight, perform steps 1-4 of Section~\ref{sec-sky} to setup the telescope and facility prior to sunset.
# Click the small grey "On" button below the SAAO CCD image display.
# Shortly before (morning) or after (evening) sunrise/set ~10 minutes after sunset for B) click "Snapshot" → Exposure time = 1s. Click "Ready" to expose.
# Hover the cursor over the top portion of the image display as the image reads out, and read off the count level in the yellow "ADU" box below the image. Assess how the exposure time needs adjusting to maintain counts of 20000-50000 as the sky darkens/brightens.
# '''During readout''' click "Expose" → acknowledge the error message → "Select" module. Click on the desired module → "Edit". Adjust the exposure time in the box at the bottom → "Replace" → "Save" → "Continue".
# Enter number of modules = 1, Image Type = Flat → Sky. Save to disk = Yes.
# When the CCD finishes reading out, click "Ready".
# Repeat steps 5-8 until you have enough flats, or until the counts are too low in that filter.
# To move onto the next filter, repeat step 6, but edit the filter number as well as the exposure time.
# Continue steps 5-9 until you have sufficient flats in all your program filters.
With practice, you will easily be able to do this before the CCD finishes reading out in 2x2 binning.
== Dome flats ==
If poor weather conditions during twilight prevent you from obtaining sky flats, dome flats can be used instead. These can be obtained at any time by imaging a "uniformly" illuminated screen in the dome in the following way:
# Follow the facility start-up procedure in Section~\ref{sec-facstartup}, but there is no need to hook the outside doors open and '''do not open the dome'''. '''Remember to open the mirror covers.'''
# Follow the appropriate '''instrument setup''' procedure in Section~\ref{sec-inststartup}.
# '''Switch on the domeflat lamp''' by turning the dial on the wall between the North pier and the blue console.
# '''Rotate the dome''' to an azimuth of 180°, such that the lamp on the catwalk illuminates the round, white screen on the dome as uniformly as possible.
# '''Slew the telescope''' to HA = -3h 16m, Dec = -14° 37'
# '''Expose and save''' at least fifteen flats for each of the required combinations of filters and binning.
You may need to adjust the dial on the incandescent lamp between filters to achieve manageable exposure times. With STE3/4, keep exposure times ≥1s to allow the shutter time to open and close.
== Observing recipes: on sky ==
The pointing model of the 1.0-metre is greatly improved in recent years, but is not quite perfect. It may be necessary to point to a bright star near your target to allow the TCS to calculate the pointing offset in each part of the sky. One set of offsets will be
applicable to a range of positions.
=== Determining pointing offsets using a bright star ===
Follow the facility start-up procedure in Section~\ref{sec-facstartup}.
# Using the Astronomical Almanac or Sutherland Almanac, select a bright star ($\sim 4^{\rm th}$~mag) near your science target (ideally within RA~30m and dec~10°).
# Check that the target and bright star selected are within the observing limits given in Section~\ref{sec-limits}.
'''On the TCS''':
# '''Initialise''' the XY-slides.
# Move the '''guide mirror into the beam'''.
# Click "TARGET" and type the RA & Dec of the bright star into the appropriate boxes, then click "SET" and "CLEAR". The coordinates will appear in yellow on the monitors above the TCS and on the observing floor to help you point to the target.
# Type the '''equinox''' of the bright star coordinates into the "SET EQUINOX" box and press "ENTER" on the keyboard.
'''At the blue console by the North pier:'''
# Switch the central toggle switches to FAST.
# Use the yellow RA \& Dec buttons to slew to the bright star, watching both ends of the telescope as well as the coordinate display monitor. You should point to within 30s (RA) and 1-2 arcmin (dec) of your target coordinates.
# Switch the central toggle switches to SLOW to commence tracking.
'''Back at the TCS:'''
# Set "Exp Time" to ~1s and "WINDOW" to "Full frame" to take images with the acquisition camera.
# Use the hand paddle for fine adjustment of the telescope to the star's coordinates, while watching the image display for the bright star to appear.
# If the bright star is not apparent, adjust "Exp Time" to ~10s and look for light from the star beaming in from one side of the image, revealing its position. Looking through the finderscope might help determine in which direction to move the telescope. If this fails, reduce the exposure time and scan the field systematically in RA & Dec.
# Once the bright star appears, select the minimum exposure time, centre the star on the image and click "P" by the target button.
# Select "ZERO POINTS" → "Enter RA & Dec of Star", then type the '''catalogue coordinates''' of the bright star into the boxes and press "SET".
# The RA & Dec zeropoints will be displayed in the message box. Note them down with the HA \& Dec as you will need to re-enter them using "ZERO POINTS" → "Enter Zeros Directly" if the TCS software is restarted, or if you return to this part of the sky after using different zeropoints in a different position. You do not need different zeropoints for different equinoxes. There is no need to note the collimation coefficient as it is ignored by the pointing model.
== Acquiring a target ==
# Follow the facility start-up procedure in Section~\ref{sec-facstartup}.
# Check that the selected target is within the observing limits given in Section~\ref{sec-limits}.
'''On the TCS:'''
# '''Initialise''' the XY-slides.
# Move the '''guide mirror into the beam'''.
# Click "TARGET" and type the RA & Dec of the target into the appropriate boxes, then click "SET" and "CLEAR". The coordinates will appear in yellow in the monitors above the TCS and on the observing floor to help you point to the target. (If you cannot see a "TARGET" button, click the "O" in the left-hand corner below the "SET EQUINOX" box.)
# Type the '''equinox''' of the target coordinates into the "SET EQUINOX" box and press "ENTER" on the keyboard.
'''At the blue console by the North pier:'''
# Switch the central toggle switches to FAST.
# Use the yellow RA & Dec buttons to slew to the target, watching both ends of the telesope as well as the coordinate display monitor. You should point to within 30s (RA) and 1-2 arcmin (dec) of your target coordinates.
# Switch the central toggle switches to SLOW to commence tracking.
'''Back at the TCS:'''
# Set "Exp Time" to ~2-4s and "WINDOW" to "Full frame" to take images with the acquisition camera.
# Use the hand paddle for fine adjustment of the telescope to the target's coordinates while watching the image display for the target field to appear. Comparison with an $8 \times 8$~arcmin finderchart is most helpful.
# The position should be accurate if you have followed the procedure in Section~\ref{sec-brightstar}, so check your zeropoints. If not, adjust "Exp Time" to search for patterns in fainter stars to compare with your finderchart. If this fails, then reduce the exposure time and scan the field by systematically adjusting RA & Dec.
# Once the target is identified, position it on the image display such that it falls on the centre of the science CCD.
* '''For STE4''', position the star approximately on coordinates (210, 270) of the TCS image display, to coincide with the centre of the science detector (for '''STE3''', approximately (180,190)).
* Move the '''guide mirror out''' to direct the beam to the science detector.
'''On the instrument PC:'''
* Take a snapshot (STE3/4) or preview (SHOC) to check the positioning of the target on the detector and adjust using the handset.
* Using '''STE3/4''', video mode can be invoked by clicking "Snapshot", entering an integration time, selecting "Video" and clicking "Ready". It can be stopped by clicking "Snapshot" and "Stop". Video mode automatically prebins the CCD, so remember to change back to 1x1 afterwards, if appropriate.
* '''For a short run of short exposures''', you may set up a module (STE3/4 - see "SAAO~CCD Camera Control Program version 1.2", J.W. Menzies) and begin to observe
'''or'''
* '''For a long run or for exposures ≥100s, you should locate a guide star and setup the autoguider before integrating on your target.
== Finding a guide star & autoguiding ==
'''On the ltsp PC:'''
* Open a terminal (click the black screen icon on the top menu panel)
* Type '''cd /usr/local/saao/40inGuiders'''
* Type '''source runit'''
'''In the DS9 interface that pops up:'''
* From the "Analysis" pull-down menu, select "DSS Server".
* In the "DSS Server" window, click on the "DSS Server" menu and select either "DSS@STSCI" or "DSS@ESO". SAO no longer connects.
* Enter RA & Dec of target (using colons to separate coordinate units) in 20'x20' field of view and click "RETRIEVE".
* Once the field image loads with the target in the centre, choose a relatively bright star outside the circle. Place the mouse cursor over the star and read off the {\bf XY slide} coordinates in the grey info area above the image.
'''On the TCS:'''
* With the '''guide mirror in beam''', click on "Move XY", then on the target star position in the acquisition image, then on "Zero XY". This centres the field on the target so that the XY slide coordinates will be compatible with those you read off DS9 for the guide star.
* Move the '''guide mirror out of beam'''.
* In "Exposures & Guiding" set "ExpTime" ~2s (adjust as necessary).
* In "XY Slides Control", click "Go To" and enter X and Y slide coordinates of chosen guide star from DS9.
* In "Pointers" click "XY+Win+G" then click the chosen guide star. This will centre the guide star on the image, window the chip and begin guiding.
* To stop or restart guiding (e.g. after brief intervals of cloud), press "GUIDE".
== TCS operations at the end of an observation ==
'''At the end of an observation:'''
* Click "Initialize" in "XY Slides Control".
* In "Exposures & Guiding" set "WINDOW" to "Full Frame".
* Move "GUIDE MIRROR" into beam to acquire next target.
'''At the end of the night:'''
* In "XY Slides Control", click "STOP" to cease A/G camera integrations.
* In "XY Slides Control", click "Initialize" to home the XY slides.
== Shutdown procedures ==
=== End of night shutdown ===
The usual shutdown procedure at the end of the night is given below. This list is printed on a laminated sign displayed in the warm room for quick reference.
# Stop instrument & autoguider exposures (TCS PC).
# Initialise XY-slides (TCS PC).
# Park telescope at HA= -1h, Dec = 0° in FAST mode (blue console).
# Switch Dome to MANUAL (blue console).
# Close mirror covers (telescope).
# Close dome shutters (Observing floor control panel - listen for beep).
# Lower wind blind (if appropriate - Observing floor control panel).
# Switch OFF telescope power (blue console).
# Switch OFF facility power at exit.
=== Closing in bad weather ===
If any of the weather limits is reached during the night, '''perform these steps first''' (you may need to slew the telescope to a
suitable position in order to access the mirror covers):
# Close mirror covers.
# Close dome shutters (listen for beep).
# Continue with the remaining steps in Section~\ref{sec-end}.
== {STE3/STE4: CCD Camera log book ==
If using STE3 or STE4, please fill in the triplicate CCD Camera log book for each image obtained, pressing hard enough for your words to register on all three sheets. If you are using SHOC, there is no such log.
The fields are explained as follows:
\begin{itemize}
\item {\bf Telescope:} 1.0-m.
\item {\bf Focus}: This is telescope focus. You may wish to make a note of
the acquisition camera focus for your own purposes.
\item {\bf CCD Type:} This will be STE3 if the unbinned detector dimensions are $512 \times 512$ pixels, else STE4 for $1024 \times 1024$.
\item {\bf CCD temp:} This refers to the ``Cu Block'' temperature reported in the ``Temperature'' section of the instrument status panel of the STE3/4 CCD Camera Control software.
\item {\bf Filters:} Enter the filter in each position of the two wheels. See Section~\ref{sec-tel}.
\item {\bf Date and Observers}: are self-explanatory.
\item {\bf Run number:} This is a 3-digit number that will apply to your data for the duration of your observing run (unlike the UCT~CCD convention). It will be prefixed to your image files, which will be named a{\em nnnxxxx}.fits, where {\em nnn} is the run number, {\em xxxx} is the file number. To determine your run number, check the previous run number in the log book and add 1.
\item {\bf File No.} is the number of the image ({\em xxxx} where the
filename is a{\em nnnxxxx}).
\item {\bf Object}: target name.
\item {\bf RA \& Dec}: it may help you to write here the exact telescope
coordinates when pointing to your target, as opposed to the
catalogue coordinates. This information, together with the
associated zeropoints, will enable you to re-acquire the target
quickly in future.
\item {\bf Equinox}: of your target coordinates.
\item {\bf Start UT}: is reported in the status panel of the CCD Camera Control software, and remains visible until the next exposure is started.
\item {\bf Start sidereal time}: can be read from the TCS coordinate display monitors.
\item {\bf Int Time}: the exposure time in seconds.
\item {\bf Preflash}: this is not required with the current detectors. This box can be used to record the prebin setting.
\item {\bf Filter and Seeing}: are self-explanatory.
\item {\bf Guide star X Y}: these are the XY-slide coordinates of the
guide star used for each observation. Read them from the TCS ``XY
Slides Control'' window while guiding, as they are not necessarily
identical to the values you read from DS9.
\item {\bf Remarks}: Any applicable notes, e.g. the RA \& Dec zeropoints for the
specific coordinates used.
\end{itemize}
== Current known issues (last updated Nov 2013)==