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Operating IRIS2

Contents




Starting up IRIS2

  1. CHECK THE SMALL WHITE BOARD NEXT TO THE TELESCOPE CONSOLE FOR THE MOST UP-TO-DATE INFORMATION ON OPERATING IRIS2.

  2. Ensure that the PTCS is running, usually on one of the virtual desktops of the triple-headed system aatxdb if IRIS2 has been in use the previous night, or perhaps on one of the Night Assistant's X-terminals.

  3. If running up IRIS2 for the very first time, log out completely from the triple-headed monitor system labelled aatxdb. From the chooser, select aatxdb as the computer to log in to. At the username prompt, enter iris_vme14 and the password given in the blue folder on the shelf just above aatxdb. A terminal window will appear and prompt you for a username and password for aatvme14; login as aatobs (If for any reason the backup control computer aatvme10 needs to be used instead, you would log in to aatxdb as iris_vme10, and the terminal window would connect you to aatvme10 by default).

  4. After login, the Drama software should be initialised. If not, then first check the blue folder and/or the small white board on the telescope console to determine which version of the software is current. You can then start it up using (e.g.):

    > ~drama/dramastart -v 19mar11iris

  5. If the IRIS2 GUI is still running from the previous night then all you need to do after 10am AEST each day is to select Commands -> Reconfigure from the System Loader GUI. This will bring up the System Configuration GUI shown below, with today's UT date, and first run number set to 1. Just go ahead and press OK, then skip to Step 10.

  6. If the IRIS2 GUIs are not yet running or have been killed, then type the following command into the terminal window:

    > start_iris2

    This will bring up the various control GUIs on the workspace of aatxdb. These include the System Loader, the IRIS2 User Interface, the Skycat Real Time Display, and the System Configuration window (shown below). This selects the data/dummy directories and file root name by default, and allows you to specify the first run number (generally you should not attempt to overwrite existing files) as well as the names of the Observers. You can leave the Observers field blank, as the archive will use the observer names entered by the Night Assistant in their log, then select "OK" (not "Cancel", else data files will be written to a completely different area).


     
     

  7. If the Skycat RTD dies for any reason, it is possible to restart it from the same terminal window you ran up IRIS2 from (or from another session if you login to aatvme14 as aatobs) by typing:

  8. > skycat &

    You must run Skycat from the aatobs home directory, as this is where the slit definition files are stored. To establish a connection between the Skycat display and the telescope (e.g. for slewing to a catalog object, or offsetting to a mark), you will need to select Telescope -> Reset Server Connection...


  9. The Skycat display should connect automatically to the data acquisition, and start showing the latest readout, together with pixel ranges and image orientation as it becomes available. If not, go to the Skycat window and make sure AAO-Detectors -> Auto Connect and AAO-Detectors -> IRIS_PROC are selected.

  10. Ensure that the detector focus is set properly in the Focus field of the Spectrograph section of the GUI. When running an observing sequence, the correct base focus and offset for a particular filter will be set automatically. To see what the current recommended base focus is, look for the line set IRIS2_BASE_FOCUS near the start of the file /export/home/aatobs/AAO_Inc.tcl. Enter the value shown there in the Focus field, then press the "Configure" button just below that.

  11. Once you have the system up and running, we recommend that you execute the Array Tests sequence, to verify the health of the detector. In the Standard Sequences menu, select "AAO_Array_Tests", and then click "Run" in the Sequences section. While this is running, start up ORAC-DR on aatlxa, and then check that the readnoise and dark current levels measured are nominal. If not, consult your support astronomer, or afternoon shift technician.



Problems with start up

If the IRIS2 system does not come up properly, there is a hierarchy of fixes:

  1. Are you trying to start it from somewhere other than the aatobs home area?
  2. Is the PTCS display updating? It may need a complete restart.
  3. Try a system Reset
  4. Kill the IRIS2 Interface and start it again.
  5. Kill the IRIS2 Interface, manually reset the IRIS2 hardware, and start it again.

If none of the above work, please contact your Afternoon Shift Technician or Support Astronomer for assistance.

The procedure for each of these steps (in turn) is:

Resetting

  1. Find the System Loader GUI on the X-terminal from which IRIS2 is being run.
  2. Select Commands->Reset
  3. The System Loader will reset all its tasks, and re-establish connections with all the other computers it needs to talk to. Eventually the System Configuration GUI (shown above) will appear. Update it if necessary and click "OK". If you are presented with a succession of error dialog boxes instead, then you will need to kill the IRIS2 interface and start it again, as described in the following section.
  4. Try a test exposure.

Kill the IRIS2 Interface and start it again.

  1. Find the aatvme14 window from which you started the IRIS2 interface
  2. In this window type cleanup. You'll get a long string of message about things being killed, removed, or otherwise expunged.
  3. Restart IRIS2 as through starting it from scratch, using the instructions above (i.e., start_iris2 on aatvme14).
  4. If everything comes back up, take a test exposure to check everthing is working. Skycat should still be left hanging around after you kill the IRIS2 Interface with the cleanup command. If not you'll have to start another one as above.
  5. Even if this doesn't work the first time, give it one more try, then go on to the next section.

Kill the IRIS2 Interface, manually reset the IRIS2 hardware and start it again.

If all the above doesn't work, you may need to manually reset some hardware. It's time to ask for help from your Support Astronomer or Afternoon Technician, as aatvme15 (the detector controller VME; note that aatvme6 is sometimes used instead) and aatvme7 (the dewar controller VME) probably need to be manually reset.

If an aatvme15 reset does not get things working then it may be necessary to reset the array controller (see image below). Go out into the Cass cage, and switch on the LEDs on the controller by holding up the LEDs On/Off toggle switch (labeled "1" below) on the third module from the right (N.B. not the one marked "PWR" just above it!). Halfway up the rightmost module is a toggle switch marked "RST" (labeled "2" below) - hold this up briefly, then release it. After a few seconds, the LEDs should start cycling again (if the GUI is running) indicating idle mode. Release the LEDs On/Off toggle switch, and return to the control room. The GUI will now need to be re-started. Find the terminal window from which it was started, and type cleanup, then start_iris2.


 
 




At the end of the night

Before going to bed, it is safest to put a BLANK in one of the wheels (usually the one in the Slit wheel is the most light-tight). This minimises the risk of any light flooding the detector during the day. The array is constantly being read even when idle, so any residual image from the previous night should be completely flushed out by the start of the next night. You can leave PTCS and Skycat running.



More details on starting IRIS2

Most of the following details are only of interest to AAO staff or very expert users. If you have IRIS2 running, proceed on to the next section below, which will explain what all those GUIs do.

Commands

There are three different commands available from both accounts for starting up IRIS2:

  iris2    -   runs the full system controlling both dewar mechanisms and detector.
  iris2dsim -  run with the dewar mechanism control in simulation but using the detector.
  iris2sim  -  run with both dewar and detector simulated. This runs entirely on the Solaris system and needs no other hardware.
 

To run the PTCS telescope system

This needs to be running before IRIS2 is started up. It may be inadvertently killed by the night assistant, should they find it necessary to kill and re-start the Guider software. Get the afternoon shift technician to initialise the CCS on the telescope console if it is not already running. Open a new terninal window on aatxdb, then hit Ctrl-d at the aatvme14 prompt to abort the login. Ssh to aatlxx as aatinst instead and type the commands:

> cleanup
> dits_netstart
> ditscmd PTCS@aatccs CRUD
> tel

Note that you can ignore the error message generated by ditscmd here. The telescope control interface should now come up and connect with the CCS. If this does not happen, type cleanup in the window from which it was started, then start again. If it still doesn't work, then seek technical help.

The IRIS2 Interface

Once IRIS2 is up and running, you should have four displays visible:

  • a System Loader window
  • the IRIS2 User Interface
  • a Skycat image display
  • the PTCS display



  • System Loader

    This shows the status of various IRIS2 sub-systems (e.g. the SPECTRO task which controls the instrument configuration, the DRT task which records the observations, etc.). These are all green when IRIS2 is running correctly. Below this is a Messages sub-window which will alert you to any problems during startup (e.g. a wheel might have failed to home properly) by highlighting them in red. There is an "Exit" option in the "File" menu, but in practice the only safe way to shut down IRIS2 is to use the cleanup command as described above.

    The "Reset" option under "Commands" will do a full reset of all tasks, and bring up the System Configuration window again.

    The "Reconfigure" option will just bring up the System Configuration window again. You should do this at the start of each night to ensure the filename dates and directories have the correct UT date.

    It is possible to send low-level TCL commands to move the wheels to non-standard positions using the "TCL Command" option under the "Commands" menu.

    IRIS2 User Interface

    This is the main configuration and control system for IRIS2. It is divided up into 6 sections:


    Instrument Configuration: is a schematic representation of the light path through the instrument as currently configured. If the light path is blocked at any point by a blank in one of the wheels, the light rays will be coloured red. Once light reaches the detector, the light rays change to blue. In imaging mode, the light rays should all come to one focus at the detector; whenever a grism is in use, dispersion is indicated by two separate light rays/wavelengths coming to two separate foci on the detector (somewhat misleadingly, this is also the case even if one of the grism wheel filters is in place).

    Whenever the observer selects a new instrument configuration from the Spectrograph section, the outline of the dewar changes from black to red; only when the observer has done a "Configure", and all the wheels/translator have arrived at their desired positions, does the outline change back to black again. Similarly, if an Observing Sequence selects a different configuration from that configured manually, the outline of the dewar will remain red. Whenever a wheel or the array translator is moving, its status will change to "Moving" in this display, and the grey circle at lower right will blink red. The "Dewar Status" display underneath should show green; if not, the dewar temperature or pressure which is out of range can be identified by selecting the "Dewar Status..." option from the "Commands" menu.



    Spectrograph: allows the observer to manually reconfigure IRIS2, though mostly this will be done as part of an Observing Sequence. There are three tabs: "Image", "Spectra", and "All" to allow changes specific to that mode only. Pull-down menus to the right of each wheel location allows the observer to select the appropriate filter, grism, cold-stop, or slit. However, only after pressing the "Configure" button underneath will all the requested changes take place in sequence. Similarly, entering a new array translator focus value has no effect until the "Configure" button has been pressed. The "Auto" option next to "Focus" will allow automatic compensation for the change in camera focus with wavelength/filter, as is currently done as part of an Observing Sequence. However, this function is not currently implemented in this "manual mode", so has been disabled. The four buttons marked "J", "H", "K" and "Ks" are accelerators, in that they not only select the designated filter, but also set Grism to OPEN_TUBE, select the appropriate coldstop based on the current top end, and then do an immediate "Configure". When using these acclerators, beware that the detector focus is not inadvertently set to 0. Similar accelerators are available for the spectroscopic modes by selecting the "Spectra" tab.

    Detector: allows the observer to set up and record a single image. The observation number of the next run to be recorded (that is not a dummy or a glance) is shown at the top. Note that "Normal" and "Fast" are exactly the same, with a minimum exposure time of 0.6 sec. "Time Series" mode can be used to save a series of exposures as a 3-D datacube (select "Keep cube"), or more commonly, is used in a `movie mode' to monitor changes in object position, focus, etc. in real time. Simply select "Time Series", "DRM", and "Glance", set the time for a single exposure, and set "Cycles" so that the sequence will run for long enough to accomplish what you wish to do.


    There are three choices for readout mode of the array:

  • DRM stands for "Double Read Mode", which consists of one read at the start of the exposure, and one read at the end of the exposure. Only the difference between these two is saved in a file. This is the optimum readout mode for broadband imaging, since it has the lowest overheads, and the data is always sky noise-limited rather than detector noise-limited. The value of "Time" is the interval between the two reads, and "N of Reads" is set to 2 by default. To cut down on disk space usage, a number "Cycles" of exposures can be averaged before being written as a single file. Further iteration is possible by setting the number of "Repeats", but for most purposes, the need to dither or the use of time-series mode (see above) makes this fairly redundant.
  • MRM stands for "Multiple Read Mode" (also known as "Up-the-ramp" sampling), in which the array is read non-destructively at several equally-spaced intervals (referred to here as the "Period"), and a fit is made to the samples at each pixel. This method is robust to cosmic rays, and yields the lowest read noise (so is preferred for spectroscopy), but has the highest overheads. The Period is set by the value of "Time", and the number of sampling periods will be one less than "N of Reads", i.e. if "Time" is 10 seconds, and "N of Reads" is 11, then the total integration time will be 100 seconds. Again, multiple "Cycles" can be averaged before writing to disk.
  • Fowler stands for "Fowler sampling", which is similar to MRM except that the array is read more often near the beginning and near the end of an exposure. This mode is not yet implemented with IRIS2.

  • There are also three types of observation:

  • Normal: the final image is displayed in Skycat, and written to disk in the iris2_data/ area with the root name and file number specified. These files will be archived.
  • Dummy: the final image is displayed in Skycat, and written to disk in the iris2_dummy/ area with the name "a.fits", then "b.fits", etc. until "z.fits", after which "a.fits" is renamed to "a.fits.old" and a new "a.fits" is created. None of these files are archived, but they can be used for "bias" subtraction in SkyCat.
  • Glance: the final image is displayed in Skycat, but not written to disk. These images cannot be used for "bias" subtraction in Skycat, nor do they have the WCS (World Coordinate System) defined.
  • The object name to be saved with a single exposure can be entered here (or during an exposure, if the integration is long enough). The "Run" button initiates an observation of the specified type. The "Dark", "Flat" and "Arc" buttons don't actually set up for any particular type of exposure, but do set the OBSTYPE keyword in the header, so that they will be archived as calibration, rather than science exposures.

    The "Save as..." button allows the observer to set the parameters for a particular type of exposure, and then recall these in an Observation Sequence by use of the DETECTOR config <config_name> command. Be careful however - if observation type "Glance" or "Dummy" is selected and saved with the config, then the images taken as part of the sequence may not be archived, or saved to disk at all!



    Messages: displays the system responses to various commands, and the progress of Observing Sequences. Also shown here are the names of the data and dummy files as they are written to disk, and the amount of disk space remaining. If you see a warning that there is space for fewer than 100 images, please alert your Support Astronomer or the Night Assistant, who will then free up more disk space.



    Window: When sub-window (individual quadrant) readouts become available, this section will allow the observer to specify which quadrant they want. Since all quadrants are read out in parallel, the use of sub-windows does not save any time in reading out, but will cut file sizes by 75%.

    Sequences: allows the observer to edit and initiate Observing Sequences, which make observing much more efficient. There are two tabs: Standard and User. Standard sequences are supplied by AAO staff astronomers, and cannot be modified by visiting observers (currently Standard and User point to the same directory, so it IS possible for a visiting observer to unwittingly overwrite a Standard sequence); they can however be copied into the User area, and modified from there. As the name implies, Standard sequences are useful for routine observing, such as photometry of standards, nodding along the slit, etc. User sequences can be defined for more elaborate types of observations. Full details on the command syntax for Observing Sequences can be found in Jeremy Bailey's overview document, or by examining those sequences already supplied. To edit or run a sequence, simply highlight it with the mouse and select "Edit" (only if a User sequence) or "Run".



    Observe Pop-Up: This pop-up window will appear once an exposure or a sequence has been initiated, and shows the current status, and time remaining (including readout overheads).
    It allows the observer the chance to set or modify the object name ("Set Object..."), or add a comment to the FITS header ("Add Comment..."). The "Stop" button will cause a sequence to pause after the end of the current exposure (this button then changes to "Continue...", allowing the sequence to be resumed). When a sequence is executing, this window will have two extra options: "Hold" and "Continue", which enable the sequence to be paused, and then re-started without exiting. An exposure in progress can safely be terminated with the"Abort" button, but note that there will be a lost file number as a result, which may upset ORAC-DR.

    Very occasionally, this window sometimes does not vanish at the end of an exposure as it is meant to. If this happens, it can be dismissed with the window manager (click on the top-left corner and select "Close"). You will then need to select "Clear Interlocks" under "File" in the IRIS2 User Interface main window to re-enable the main functions and commence a new exposure. You may be better off doing a full "Reset" from the System Loader window.




    Skycat Image Display


    The image display for IRIS2 is built upon the ESO Skycat tool, with some extra capabilities added to enable interaction between IRIS2 and the telescope. The display is updated in "real time", that is after each read of the array (or every 5 reads if in MRM mode). Both Normal and Dummy runs come with full World Coordinate System (WCS) information in the FITS header, so that astrometry is possible (however you may need to Open a dummy image in Skycat in order for its WCS tio be recognised, e.g. when trying to move a target to a particular mark or reference). While the absolute coordinates are only as good as the last pointing ("SNAFU") star that was measured, the relative coordinates should be accurate enough to associate catalogued objects with their image counterparts.

    When viewing old images or DSS images while taking new data, you may wish to temporarily suspend the real-time display. You can do this by de-selecting AAO-Detectors -> Auto Connect, then selecting AAO-Detectors -> Auto Connect when you are ready to resume the real-time display. If the IRIS2 User Interface needs to be restarted for any reason, then the display server connection to the telescope can be re-established by selecting Telescope -> Reset Server Connection...

    Some information on the main features of Skycat can be found on the ESO Skycat Web pages. We will only describe here the features particular to IRIS2.

  • Bias image: Quite often in infrared astronomy, the sky signal swamps that from the source, and it is only by subtracting an image of the blank sky (or any region of sky offset from the object of interest) that the source starts to become visible. To assist this process, Skycat allows the user to define an image (referred to here as the bias, but could be any type of image) which is to be subtracted from all subsequent images before they are displayed. To enable this process, select File -> Bias Image... This brings up another window from which up to five different bias images can be pre-loaded. To load the first bias image, click on the "Load" button in line 1, which brings up a file browser. Select the image you wish to subtract, then click "OK". To turn on bias subtraction, select "Subtract". Alternatively, whatever image is currently shown in the Skycat display can be set to be a bias image by clicking "Copy image -> bias". You will most likely have to do an "Auto Set Cut Levels", or set the Low and High cut levels manually to scale the bias-subtracted result. To disable bias subtraction, simply de-select "Subtract" in this window.

  • Reference Pixel: Currently, the WCS in the FITS header is defined relative to a reference pixel at (460,460), i.e. near the top-right corner of quadrant 2. At the start of each run, the night assistant will use the APOFF program in the CCS to define Aperture A for IRIS2 imaging by positioning a pointing standard in this pixel. The better the current pointing model, and the closer the target to the last pointing standard, the better will be the absolute astrometry. The location of the reference pixel can be shown by selecting AAO-Detectors -> Mark Reference Pixel (or hidden using AAO-Detectors -> Clear Reference Pixel Mark). To place the object of interest at the Reference Pixel, position the cursor over it, then hold down the Shift key while left-clicking the mouse. This will bring up a list of options, the first of which is "Move object to reference pixel (460,460)". Selecting this option will cause Skycat to pass the necessary offsets to the PTCS (using the WCS), which will then offset the telescope accordingly.

  • Marks: Besides the Reference Pixel, there are two additional Marks that can be set by the user. Holding down the Shift key while pressing the left mouse button will bring up a list of options, including "Set mark 1 here" and "Set mark 2 here". Once one or both marks have been set, it is possible to have the telescope move any other object in the field to that pixel, by Shift+left-clicking on that object, and selecting "Move object to mark 1" or "Move object to mark 2". The confirmation dialog that comes up whenever a telescope move is requested will specify not just the RA and Dec to move to, but also the offsets in arcseconds, and (for the benefit of the night assistant), the equivalent guide probe offsets which would achieve the same result. This is the preferred option when acquiring an object for spectroscopy; coarse alignment is done by moving close to a mark on the slit axis, a guide star is acquired, and fine-tuning is done by offsetting the guide probe. The marks can be temporarily hidden by selecting Telescope -> Hide Marks, or restored with Telescope -> Show Marks. In addition, the offset between them (in arcseconds of RA and Dec) can be called up with Telescope -> Show Offset between Marks.

  • Slew to Catalog Object: By calling up the coordinates of an object from a database like NED or SIMBAD using the "Data Servers" menu, then highlighting that object in the list of sources found, the coordinates of that object can be passed direct to the CCS and the telescope slewed there by selecting Telescope -> Slew to Selected Object. If Skycat has just been started, you will need to precede this with a Telescope -> Reset Server Connection... You can also call up targets from a catalog of your own, as in this example, in which object ID, RA, and Dec are separated by a <TAB>, you should save it with a .tab extension, then call it up from Data-Servers -> LocalCatalogs -> Load from file.... Note that even a single extraneous character in any line of this file can result in the catalog file not being loaded at all, or cause Skycat to hang after requesting a Slew.



  • PTCS

    The Portable Telescope Control System (PTCS) duplicates much of the functionality of the telescope control console and night assistant's terminal. It allows the observer to switch between the Reference axis "R" (which is the default whenever a slew occurs) and the pre-defined apertures "A" and "B". From the "Commands" menu, select "New Target" and enter the RA, Dec, Epoch, proper motion, etc., then hit "Slew" to send the coordinates to the Control Computer System (CCS); this may take a few seconds - watch the CCS terminal, which should load the new coordinates and commence the slew. Although the PTCS cannot access or store a file of coordinates like the CCS can, it is possible to call up catalogued objects by name, or from an input catalogue provided by the observer, using the "Slew to Catalog Object" function within the Skycat display.

    To command a specific offset, the observer must first click on the green "Control OFF" button, which will then change to "Control ON" highlighted in yellow. Select Commands -> Offsets... and enter the offsets in arcseconds. Note that for RA, the offsets are in arcseconds on the sky, not arcseconds of polar axis rotation as they are on the night assistant's console. Offsetting the telescope to place the target on or near a particular pixel is best done using the Skycat image display. To go back to the Base position, select "Centre". Note also that switching Control ON (which can also be commanded from an Observing Sequence) makes the current telescope position the new Base position.



    Return to the main IRIS2 page.

    These pages contain information on the functionality of the IRIS2 Infrared Imager and Spectrograph. Pages maintained by Angel Lopez-Sanchez (alopez -@- aao.gov.au) and Stuart Ryder (sdr -@- aao.gov.au) Page last modified by Stuart Ryder.