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. End of night
7. Shutting down the system
8. Writing data tapes
9. 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 to the Sun workstation taurus (next to the ICL computer):
  
  • LOGIN: whtobs
    PASSWORD: provided by your support astronomer
  An openwindows session starts, and an xterm pink window (labeled "Central intelligence of observing system") and several xterm orange windows will appear. Also a netscape window appears, which shows the UltraDas Software Operations Manual (command dictionary included).
  Minimize all the orange windows except the one corresponding to the DAS (data adquisition system) computer which controls INGRID (get its name from the white board above the ICL computer). It is entitled DAS at the moment (July 2002).

• Start the data adquisition system:
  • Type obssys in the DAS (orange) window. It defines the software to use and will then prompt you to select the observing system. Type the option number corresponding to INGRID (option 22 for INGRID at Cass at the moment (May 2002)) and wait until the prompt DAS> appears.

  • Type DAS>startobssys to start the software. Wait until the prompt is back and minimize this window (it is not needed until you shut down the system).

• Start the system computer:
  • Type obssys in the pink window.

  • Enter the same option number as in the orange DAS window and wait to get the prompt SYS>.

  • Type SYS>startobssys
    This initializes the telescope control software (TCS) link, the INGRID mechanism controller and the INGRID SDSU controller, and brings up several new windows:
    • A real time display (RTD) control tool
      
    • An Ximtool to display the data
      
    • The INGRID mechanism mimic.
      To get more detailed information about the INGRID mechanism wheels, select Control from the File menu.
      
    • An "identify" window.
      Enter your name and proposal identification.
      
    • The observing log.
      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.
      
    • The array info display window
      
    • The "talker" window. It displays messages from the observing system to the user.

• SYS>fwheel1 ingrid datum;fwheel2 ingrid datum;pstop ingrid datum
  Initialize the pupil stop wheel and the two filter wheels. Check that the motor readback position after datum in all wheels is close to 0.169 (if that is not the case in any wheel, datum it again).

• If you want, you can bring up a telescope info display window. Type:
  SYS>tcsinfo&
  

• Set the array readout speed to slow:
  SYS>rspeed ingrid slow
  The fast speed readout is not available at the moment (24/7/2002).

• To examine INGRID data:
  
  • Log on to lpss13, the sparc station dedicated to INGRID quick look reduction (the monitor 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 ( e.g. cl>cd /obsdata/whtb/20010501).
  • Type: cl>ingrid in IRAF, to start up the INGRID quick look reduction package.

• Now is a good moment to take two darks of the same exposure time and measure the INGRID array readout noise:
  • SYS>filter ingrid blank Put blanks in the light path.
  • SYS>dark ingrid 2 "dark 2s a" Take the first dark frame.
  • SYS>dark ingrid 2 "dark 2s b" Take the second dark frame.
  • On lpss13, within the ingrid quick look package, type: in>ifindron and enter the filename of the two darks. The result is given in ADU.

  IMPORTANT: the readout noise value given in the image FITS headers is fixed, and regularly updated, but not derived from each specific image. Observers are therefore recommended to check the readout noise of their images.

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 extensions 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 28000 ADU to alert observers to saturation. The pixels are also turned red when either the value in the pre or in the post is higher than 43000 ADU.
   The change to UltraDas moved the full well limit up to ~30000ADU (it was 22000 ADU before 1 Sept 2001). Non-linearity is ~± 2% over the range 0-12000 ADU (in the post-pre) at the moment.
   More information is given here.

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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:
    SYS>mchstat
  • Click here to see the filters and pupil stops currently available on INGRID.

• 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.: SYS>fwheel1 ingrid datum (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).

  • From the command line in the ``pink window''
    • Filters. Filter wheel movements can be performed with the commands fwheel1 ingrid <filter name> or fwheel2 ingrid <filter name> for broad band and narrow band filters respectively. It is however recommended to use the command filter:
      SYS>filter ingrid <option>, where <option> can be blank, clear z, j, h, ks, k, h-barr, ks-barr, fe, brg, kcont, hcont, h2v1_0, h2v2_1, pab, jcont. 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	blank1
      clear	clear	clear	clear
      z	cass-j	z	clear
      j	cass-j	j	clear
      h	cass-h	h	clear
      ks	cass-k	ks	clear
      k	cass-k	k	clear
      h-barr	cass-h	h-barr	clear
      ks-barr	cass-k	ks-barr	clear
      fe2	cass-h	h	fe2
      brg	cass-k	ks	brg
      kcont	cass-k	ks	kcont
      hcont	cass-h	h	hcont
      h2v1_0	cass-k	ks	h2v1-0
      h2v2_1	cass-k	ks	h2v2-1
      jcont	cass-j	j	jcont
      pab	cass-j	j	pab

    • Pupil stops can be changed independently of filter movements with the command:
      SYS>pstop ingrid <option;>, where <option;> for observations at the Cassegrain focus are:
      
      • cass-j,h,k  Pupil stops with central obscuration, used for observations at Cassegrain in the j, h and k band respectively.
      • clear No pupil stop in the beam.
      • blank1  Aluminium blank for dark frames acquisition.
      Other options are: naomi-obs, naomi-clr, osca-clr, osca-obs, ker, kel,cass-s, where obs stands for pupil stops with central obscuration and clr for pupil stops without central obscuration. Click here for details on the dimensions of the pupil stops.

    • INGRID focus drive. Type SYS>ifocus ingrid <position in microns>.

    • Pupil imager. Only used in engineering mode. In normal astronomical use the pupil imager position must be out of the light beam. Call your support astronomer or duty engineer to take the pupil imager out if necessary.

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IMPORTANT: Please, follow this temporary procedure to focus INGRID until further notice. In summary, it consists of:
(a) setting the INGRID focus to +50 microns, (b) focus the telescope with the normal procedure (described below) but using only stars located in the center of the array, (c) finally subtract -140 microns to INGRID internal focus.

• Focusing the telescope

  The best telescope focus value for observing with INGRID is ~99.05mm (May 2003). 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:
    SYS> filter ingrid h

  • Take a sequence of images for different values of the telescope focus using the command focusrun followed by:
    • the number of images (i.e. number of telescope focus movements),
    • the exposure time,
    • the telescope focus value for the first image in the sequence (in mm) and
    • the focus increment between each image (in mm)
    *Example:
    
    SYS>coave ingrid 2, set to 2 the number of coaverages (of the exposure time given below) performed in each image of the sequence.
    SYS>focusrun ingrid 9 8 98.1 0.1
    In this case, nine files (e.g. r559685.fit, r559686.fit,...,r559693.fit) would be saved on disk, corresponding each to a telescope focus value (starting at 98.1mm 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 lpss13, in the iraf session and within the INGRID quick look reduction package (see the last item in section 1), type:
    in>istarfocus r559685 nim=9
    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.:
    
    SYS>focus 98.6
    
    since the telescope focus is left to the last value of the sequence after running focusrun.

  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 <>):
  • rmode ingrid mndr < Nr> < N coav>
    Sets the number of MNDR (multiple non-destructive reads) to Nr and the number of coaverages to N coav. 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). N coav is the number of accumulated exposures that are averaged and written as a single output file.

  • coave ingrid < N coav>
    Sets the number of coaverages to N coav.

  • multglance ingrid <N> < int time>
    Produces a sequence of <N> exposures of the required integration time. E.g.: multglance ingrid 999 2 produces a sequence of 999 2s exposures. The sequence can be finished by pressing control-C.

  • run ingrid <int time> <"title">
    Takes a run and saves it in: rxxxxxx.fit.
    E.g. run 8 "FS33 ks", an 8 second exposure and store it in the output file (e.g. r240976.fit).The title of the fits file is set to "FS33 ks". If the number of coaverages has previously been set to 2 (i.e. coave ingrid 2 or rmode ingrid mndr 1 2) the command run 8 "FS33 ks" takes two 8 second exposures in succession, then coaverages the data before storing in the output file (e.g. r240976.fit).

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

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

  • glance ingrid <int time>
    Takes an exposure and saves it in s1.fit. This file is overwritten when a new glance is taken.

  • scratch ingrid <k> < int time> <"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 ingrid <m> <int time> <"title">
    Same as run but repeats the run sequence m times and generates m output files.

  • multflat ingrid <m> <int time> <"title">
    Same as flat but repeats the run sequence m times and generates m output files.

  • multdark ingrid <m> <int time> <"title">
    Same as run but repeats the dark sequence m times and generates m output files.

  • dithern ingrid <int time> <x offset> <y offset><"title">
    Takes n runs with the required integration time (and number of coaverages previously set) 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.

  • ag_dithern ingrid <int time> <x offset> <y offset><"title">
    Same as before, but with autoguided telescope at each dither position. Run it after the TO has found a suitable guide star and has done a "field".

  The arguments above stand for

     < int time> Integration time in seconds.
     < "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 and temperature of the monitoring points.
  • mchstat Shows mechanisms and INGRID controller status

• 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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• If for any reason a failure occurs when running an observing script, slew the telescope to the object position and restart it again.

• If the RTD control panel disappears, type the following in the pink window:

  SYS>startrtd&

• The orientation in the INGRID images is North down, East right when the rotator position angle is 0 degrees. Tell the TO to set the rotator position angle at 180 degrees if you want to have North up, East left in your INGRID images.

• The scheme below shows how stars move when applying a positive offset or aperture with sky PA=180 (e.g. aperture 1 100 100, moves the star 100" E and 100" N, i.e. left and up).

          APERTURE  OFFSETS                          OFFSETS  (ARC)                           
                        
                  N
        +------------------+  sky pa=180          +------------------+  sky pa=180 
        |                  |                      |                  |  
        |             ^    |                      |                  | 
        |             | y  |                      |      x           |
        |             |    |                      |  *------>        |
     E  |             |    |                      |  |               |
        |       <-----*    |                      |  | y             |
        |         x    	 |                      |  |               |
        |             	 |                      |                  |
        |       	         |                      |                  |
        +------------------+                      +------------------+
  
  
  

• 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. 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:

    SYS>filter ingrid blank

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

    SYS>dark ingrid 10 "dark 10s"

    This takes one dark frame of 10s exposure time 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: 15 December 2003 Almudena Zurita, azurita@ing.iac.es