1. Starting the system
2. INGRID real time display (RTD)
3. INGRID mechanisms
4. Focusing
5. INGRID observing commands
• INGRID data acquisition commands
• INGRID diagnostic commands
• TCS commands
6. Shutting down the system
7. Writing data tapes
8. Important notes

• First confirm that the light from the WHT is directed to INGRID. On the ICL computer type:
  agingrid
  The light will now be directed to INGRID and this will be reflected on the ICL mimic.

• Log on remotely to crater from the Sun workstation taurus (next to the ICL computer):
  
  • In the Options menu of the login window, choose Remote login, Enter host name.
  • Type crater, and a new login window will appear.
  • LOGIN: ingrid
    PASSWORD: provided by your support astronomer
  An openwindows session starts, and a pink instrument control window appears, entitled ``Ingrid Observing System'', with the local time in the prompt: hh:mm:ss>.
  Also a netscape window appears, which shows the IMP Software Operations Manual (command dictionary included).

• Type hh:mm:ss>obssys in the pink window. Up to date information on observing with INGRID will be displayed. Hit return to continue. It will then prompt for:
  
  • Version of the observing system to be used: get it from the news previously displayed or from the general white board behind you. Type the corresponding number and press return.
  • Disk where the data will be stored: select the partition with the greatest space available. Type the corresponding number and press return.
  • Directory where the observational data will be stored. Accept the default (which should be the current date in the format yyyymmdd) if it is correct.
  A summary of the final configuration will be displayed and the control will be returned to the terminal prompt.

• Initialize the observing system:
  hh:mm:ss>startobssys
  This initializes the telescope control software (TCS) link, the INGRID mechanism controller and the INGRID SDSU controller, and brings up two new windows: a real time display (RTD) control tool, and an Ximtool to display the data.

• Bring up the ingrid mechanism mimic:
  hh:mm:ss>disp_ingrid&
  To get more detailed information about the INGRID mechanism wheels, select Control from the File menu.

• Bring up the observing log window:
  hh:mm:ss>obslog&
  The log is automatically updated each time a new file is written to disk. To put comments on a file click once with the mouse on the file and a box appears where you can type shorts comments.

• Bring up the TCS information window
  hh:mm:ss>tcsinfo&
  

• hh:mm:ss>datum all
  Initinialize the pupil stop wheel, the two filter wheels and the array focus. Alternatively, the mechanisms can be initialized separately by typing: datum fwheel1, datum fwheel2, datum pstop and datum focus.

• To examine INGRID data:
  
  • Log on to lupus, the sparc station dedicated to INGRID quick look reduction (two monitors on the right of taurus):
    LOGIN: whtguest
    PASSWORD: provided by your support astronomer.
  • Open up an xgterm (type xgterm -sb&).
  • Open up an Ximtool (type ximtool&).
  • Start an IRAF session (type cl or ncl) from the home directory (/home/whtguest), in the recently opened xgterm.
  • Change to the disk and directory where the data is going to be stored (selected after running obssys; e.g. cl>cd /obsdata/whtb/20010501).
  • Type: cl>ingrid in IRAF, to start up the INGRID quick look reduction package.

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1. RTD control panel. INGRID fits data files contain two extensions (e.g. r414230.fit[*,*,1] and r414230.fit[*,*,2]) which correspond to the array readout after the reset process and before the integration (the pre-read, extension 1) and the readout of the array after integration has finished (the post-read or post-integration data set with extension 2). Click here for a more detailed explanation.

   The RTD control panel (image below) includes several options which allow the user to display either the post-read or the pre-read image extentions or the post-pre (=post minus pre) image of a certain observation data. Also, it is possible to display the result of subtracting one image from another (e.g. a sky subtracted image). This operation affects only the displayed data (i.e. only raw data is stored on disk).
   

   

   On the RTD control tool window, from top to bottom:

   • Observation data Shows the file name of the image actually displayed on the Ximtool.
   • Reference data Shows the file name of the image loaded as reference data (see below).
   • Status Status of the RTD. It can be ``scanning'' if the Data detection is selected to be on (clicking on the corresponding diamond), or ``data detection off'' if Data detection is off.
   • Data directory Shows the directory where the data is being stored.
   • Data detection If you click on the on box, the new images are automatically loaded into the RTD.
   • Display state This section offers several options to display the data, which are activated by clicking on the diamonds on the left:
     • OBS-REF Displays the post minus pre of the observation data minus the post minus pre of the reference data
     • OBS/REF pre Displays the pre-read of the observation/reference data
     • OBS/REF post Displays the post-read of the observation/reference data
     • OBS/REF post-pre Displays the post minus pre of the observation/reference data
   • Refresh Click on this button to refresh the display on the Ximtool.
   • OBS->REF Load the current observation data as reference data.
   • Quit Click on this button to quit the RTD.
   • Load OBS/REF data These buttons can be used to load any fits files of the Data directory as Observation data/Reference data: type the file name of the image in the corresponding box and click the corresponding button.
   In the example of the figure, the post minus pre of the file s1.fit is displayed on the Ximtool and no data has been loaded as reference frame.

2. Ximtool It is a typical Ximtool image display window but in addition it turns red the pixels which value in the post minus pre of the data set is higher than the full well (22000 ADU).
   For values higher than 22000 ADU in the post-pre, deviation from linearity starts to be high (higher than ~8%) and pixels are shown in red. Since the full well could vary slightly, keep away from this limit by decreasing your exposure time, if necessary.

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• Status of INGRID mechanisms

  The position of the filter wheels, the pupil stop wheel, the instrument internal focus and the pupil imager can be checked by means of the mechanisms' windows or using a line command:
  

  

  • The INGRID mechanism mimic summarizes the selected positions of the filter and pupil stop wheels, the pupil imager and the instrument internal focus value in microns.
    A graphical user interface (GUI) can be obtained from the File menu, selecting Control. The selected positions in each wheel are coloured green.
  • In the pink instrument control system window, the command mchstat shows the status of the INGRID controller and all the mechanisms:
    hh:mm:ss>mchstat

• Moving INGRID mechanisms

  Mechanisms can be moved using either the GUI or the command line interface (pink window), however it is recommended to move them using the command line.

  • From the GUI
    • Filters and pupil stops. To move any of the three wheels, click on the filter/pupil stop you want in the beam. Whilst moving, the whole wheel is coloured blue and the selected position yellow. When the wheel movement has finished the demanded filter turns green (success) or red (undefined position). If the latter occurs, you have to datum the corresponding wheel (click in the datum button or type e.g.: hh:mm:ss>datum fwheel1 (or fwheel2, or pstop)). IMPORTANT: the motion of two wheels simultaneously can result in losing wheel accuracy and hence it is not recommended.

    • Focus drive. To select an array focus value, type the required focus value in microns in the box and hit return). Not currently available (01/07/2001).

  • From the command line in the ``pink window''
    • Filters. Filter wheel movements can be performed with the commands fwheel1 < filter name > or fwheel2 < filter name > for broad band and narrow band filters respectively. It is however recommended to use the command filter:
      hh:mm:ss>filter < option >, where < option > can be blank, z, j, h, k_s, k, fe, brg, kcont, hcont, h2v1-0, h2v2-1. Using the filter command, filter movements are tied to other filter movements and/or pupil stop movements to eliminate as much unwanted radiation as possible before entering the camera, therefore it is recommended to change the filters this way. These filters-pupil stops combinations are:

      < option >	Pupil stop wheel	Filter wheel 1	Filter wheel 2
      blank	blank1	blank2	blank4
      z	cass-l	z	clear
      j	cass-s	j	clear
      h	cass-s	h	clear
      k_s	cass-l	k_s	clear
      k	cass-l	k	clear
      fe2	cass-s	h	fe2
      brg	cass-l	clear	brg
      kcont	cass-l	clear	kcont
      hcont	cass-s	h	hcont
      h2v1-0	cass-l	k_s	h2v1-0
      h2v2-1	cass-l	k_s	h2v2-1

    • Pupil stops can be changed independenly of filter movements with the command:
      hh:mm:ss>pstop < option >, where < option > for observations at the Cassegrain focus are:
      
      • cass-s  Pupil stop with short central obscuration. Used for observations at Cassegrain with wavelength < 2µm
      • cass-l Pupil stop with large central obscuration: used for observations at Cassegrain with wavelength > 2µm.
      • clear No pupil stop in the beam.
      • blank1  Aluminium blank for dark frames acquisition.
      Other options are: naomi-s, naomi-l, osca-clr, osca-obs, ker, kel, focus.

    • INGRID focus drive. Type hh:mm:ss>ifocus < position in microns >. INGRID internal focus is currently fixed (01/07/2001).

    • Pupil imager. Only used in engineering mode. In normal astronomical use the pupil imager position must be out of the light beam. Type hh:mm:ss>pimager out if necessary.

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• Focussing the telescope

  The best telescope focus value for observing with INGRID is ~98.0mm. Use this value as a starting point.
  • Select a star of magnitude ~10-11 and tell the telescope operator (TO) to slew the telescope to it.

  • Select a filter. Since no focus offset has been observed between different broad band filters, use either filter H or J to avoid high background levels in the images:
    hh:mm:ss> filter h

  • Take a sequence of images for different values of the telescope focus using the command whtfocusrun followed by:
    • the number of images (i.e. number of telescope focus movements),
    • the exposure time,
    • the number of coaverages (of the exposure time given) performed in each image of the sequence,
    • the telescope focus value for the first image in the sequence (in mm) and
    • the focus increment between each image (in mm)
    *Example:
    
    hh:mm:ss>whtfocusrun 9 8 2 97.6 0.1
    In this case, nine scratch files (s1.fit, s2.fit,...,s9.fit) would be saved on disk, corresponding each to a telescope focus value (starting at 97.6mm with steps of 0.1mm) and obtained after coaveraging two 8s exposures.
    It is recommended to expose at least a total of 10-15s in each image in order to average out seeings effects.

  • Find the best telescope focus value: on lupus, in the iraf session and within the INGRID quick look reduction package (see the last item in section 1), type:
    in>istarfocus s1,s2,s3,s4,s5,s6,s7,s8,s9
    and follow the instructions (i.e. mark with an m one or more stars in the image, type q and wait until an xgterm appears showing the fwhm and ellipticity plotted versus the telescope focus value (in meters, m), and finally type q again to find the best value). NOTE: The best telescope focus value is given also in m.

  • IMPORTANT: Set the telescope focus value to the best value determined above (in mm) e.g.:
    
    hh:mm:ss>whtfocus 98.1
    
    since the telescope focus is left to the last value of the sequence after running whtfocusrun.

  If the seeing is very good, repeat the telescope focus procedure with smaller steps (e.g. 0.05mm).
  

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• INGRID data acquisition commands
  Some of the most important commands related to data acquisition are listed below (arguments are denoted by <>):
  • numreads < Nr>Sets the number of MNDR (multiple non-destructive reads) to Nr.
    Nr is the number of times that the array is read not-destructively prior and after an integration period. The array data from the Nr pre and post-integration reads respectively are averaged independently. Nr is an integer between 1 and 16 (default is 1; i.e. correlated double sampling).

  • run < int time> < N coav> <"title">Takes a run and saves it in: rxxxxxx.fit.
    E.g. run 8 2 "FS33 ks", takes two 8 second exposures in succession, then coaverages the data before storing in the output file (e.g. r240976.fit). The title of the fits file is set to "FS33 ks".

  • dark < int time> < N coav> <"title">Takes a run and set the OBSTYPE header parameter to DARK (arguments are described below).

  • flat < int time> < N coav> <"title"> Takes a run and set the OBSTYPE header parameter to FLAT.

  • glance< int time> < N coav> Takes an exposure and saves it in glance.fit. This file is overwritten when a new glance is taken.

  • scratch < k> < int time> < N coav> <"title"> Takes a run and saves it in: sk.fit.k is an integer within the range 1-99. The scratch file sk.fit is overwritten when a new scratch< k> is taken.

  • multrun < m> < int time> < N coav> <"title"> Same as run but repeats the run sequence m times and generates m output files.

  • dithern < int time> < N coav> < x offset> < y offset><"title">
    Takes n runs with the required integration time and number of coaverages and moves the telescope between them using the quantities entered on < x offset>, < y offset>. Each run is saved in a fits file (rxxxxxx.fit). n defines the dither pattern and can assume the values 2, 3, 4, 5, 8 and 9. In all cases the telescope starts and ends at the centre of the pattern.

  The arguments above stand for

     < int time> Integration time in seconds.
     < N coav> Number of coaverages. Number of accumulated exposures that are averaged and written as a single output file.
     < "title"> Title of the exposure recorded in the image header (optional argument).
     < x offset> Telescope offsets in arcsec.    < y offset>

• INGRID diagnostic commands
  • detstat Shows detector status
  • mchstat Shows mechanisms and INGRID controller status
  • tcsstat Shows status of the TCS link
  • wheelcon Displays a list of the various optical components loaded into INGRID's mechanisms

• TCS commands
  • user ENTER APERTURE <number> <ra offset> <dec offset>
    Defines the aperture < number> characterized by <ra offset> and <dec offset> arcsec offsets in RA and DEC respectively (e.g. user ENTER APERTURE 1 -400 0)
    
  • aperture <number>Offsets the telescope according to the previously defined aperture
    
  • offset arc <ra offset> <dec offset>Offsets the telescope by <ra offset> arcsec and <dec offset> arcsec in RA and DEC respectively from the nominal position
    
  • gocat <object_name>Moves the telescope to the object <object_name> if this has previously been loaded into the TCS
    
  • object <object_name> <ra(hh mm ss.ss)> < dec(dd mm ss.ss)> <equinox>
    add Adds the object <object_name> to the catalog

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• The SDSU controller sometimes fails and the observations are stopped. Type hh:mm:ss>recover in the pink window if a failure occurs. After this, if the failure happens when running a script, slew the telescope to the object position and restart it again.

• Remember to take dark frames of the same exposure time of your science frames. The dark level for the INGRID array can not be scaled with time, since there is a non-linear (exponential) increase in the dark level at low exposure times (up to ~1min). To take dark frames:
  • In the iraf session and within the INGRID quick look reduction package, use the task ilistdark to get a list of the exposure times of all your INGRID science frames; e.g.:

    in>ilistdark r*.fit

  • Put blanks into the light path:

    hh:mm:ss>filter blank

  • Take the darks of the exposure times listed by ilistdark using the command dark. E.g.:

    hh:mm:ss>dark 10 1 "dark 10s"

    This takes one dark frame of 10s exposure time with one coaverage and the title of the FITS image is set to "dark 10s". You can generate an observing script to get the dark frames for the exposure lengths needed and then execute it from the command line.

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Last Updated: 7 August 2001 Almudena Zurita azurita@ing.iac.es