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NAOMI Setup and Observing Recipes

The recipes below cover typical setup and observing procedures required during routine operation of NAOMI in NGS mode.

Mirror flattening is covered in a separate document.

For observations using the laser guide star, consult instead the GLAS setup/observing recipe, which is more up-to-date (but these pages still contain more detail on a few topics).

There is a separate (supplementary) observing recipe for OASIS. For troubleshooting and diagnostic procedures, see the troubleshooting guide.

Links to the home pages of NAOMI and the individual science instruments are given at the head of this page.
For technical information, see the NAOMI technical-information page, which includes links to e.g. a description of NAOMI (component-by-component), a collection of useful numbers (parameter ranges and settings, conversion factors etc.) and the engineering documentation index.

The sections below describe basic daytime checksto be carried out by the ops team or by NAOMI specialists:

The above sections are preceded by a quick-reference check-list, which may be useful for experienced users.

The duty engineers have their own daily-checks list, maintained by Olivier Martin.

The full checks should be carried out by the ops team a few days before the run (to allow time to fix any problems) and on the day of the run. Thereafter, the ops team will carry out only the first part of the checks (i.e. not including mirror-flattening), unless (1) the night-time observer requests that the mirror be flattened (e.g. because the mirror shape has seriously degraded during the night), or (2) the PSF as seen on the simplex camera is obviously degraded.

It's assumed that when the above checks are carried out by the ops team, a NAOMI specialist will be on-call at SLO to help with any unexpected problems (ops-team staff aren't expected to navigate the troubleshooting guide!).

The remaining sections deal mainly with night-time operation of NAOMI, and are aimed at NAOMI support astronomers:

Please send corrections to Chris Benn ( Below is a brief summary (not comprehensive) of the steps involved in carrying out the daytime checks and mirror-flattening. The procedures are described in detail in the rest of the document.


  • GRACE: covers off; check surfaces, pinhole (usually 2- or 5-micron), light path; check required sub-systems are powered on.
  • On the air-conditioning control panel in the control room, check that the temperature is stable.
  • Run up observing system on taurus, check detectors are available.
  • Check that CODESO gui has come up (otherwise telnet to lpss94 to start it up), float the bench.
  • Start top gui from lpss42 prompt with topgui (use restart if any problems), load last flat, close SG loop (C40s page), check SG gain, start WFS framing, click on 'continuous', set max to 2000 counts.
  • Put simplex pinhole in beam, switch on lamp, set pickoff probe to nominal position (~ 0, 3), put in good-seeing lenslet, check spots are present on WFS.
    The simplex pinhole can be moved manually in the vertical direction. The current (9/06) position is 6.8 mm. It's rarely moved, so it's not necessary to check it.
  • Run up simplex gui, put in simplex flat mirror, check that pinhole image is visible on AG7. Check appearance of PSF, to decide whether mirror-flattening required (always required on the first night of a run).
  • Take simplex flat out, set OASIS to imaging mode, check that pinhole image is visible on MIT3, if required.
  • Take out OASIS flat, check that pinhole image is visible on INGRID, if required.

Click here for the mirror-flattening checklist (separate document)

Final checks by support astronomer:

  • Final simplexing, for each dichroic to be used at night.
  • Measure offsets for each simplex, and for each required WFS mode, using AutoOffsets.
  • Load NAOMI (not electra) reconstructor, test it closed-loop (for each WFS mode).


GRACE is positioned at the head of the stairs when the WHT azimuth is 300 deg. While in GRACE, be careful - bear in mind that you are effectively inside the instrument!

The photo below (from Myers et al 2002) shows the layout on the NAOMI optical bench of the deformable mirror (DM), off-axis paraboloid (OAP1, = fast-steering mirror, FSM) and wavefront-sensor (WFS). Since the photo was taken, the NCU has been upgraded, and OASIS, the ADC and the simplexing camera have been added.

  1. The covers should be removed from:
    • the first off-axis paraboloid (OAP1 or FSM, to the right of the deformable mirror (DM) when standing in front of it)
    • the large fold-flat mirror (between the DM and the edge of the bench)
    • the DM (photo of DM in lab from Myers et al):

    • the fisba return flat (right of the DM, next to the rail)
    • the small fisba mirror (with a cover marked "FISBA COVER" (above the rail) (the cover's a bit stiff, don't jerk it))
    • the second off-axis paraboloid (OAP2, at the right hand end of the rail)
    • the Nasmyth derotator (unless light leaking in from the dome is likely to hamper daytime work)
    The covers should be removed with care, to avoid disturbing the optical alignment, leaving fingerprints on an optical surface, or knocking the surface of an adjacent component.
    The DM cover should be removed with particular care. The DM is irreplaceable. Also, the DM surface cannot be cleaned. The cables going into the DM chassis should not be touched.
    The covers are usually left off during a run, and replaced between runs.
    Be careful with your fingers near the ADC (if present on the bench) - it can move suddenly into the beam (e.g. shortly after a reboot of the USP controller), with the cog slicing past the edge of the OAP1 mount.
  2. If any of the optical surfaces appear dirty, ask an expert (in optics or NAOMI) to blow off dust with the rubber bulb (kept in the cupboard behind the bench).
  3. Check that the required pinhole is installed in the NAOMI simplex position (leftmost aperture) in the Nasmyth calibration unit (left edge of the bench, when standing in front of the DM). For setup, the 2-micron pinhole is required. 5- and 10-micron pinholes (and larger) are also available. The pinholes, in screw-thread plastic mounts, are kept in small white envelopes in a box usually left on top of OASIS. If a pinhole is removed from the NCU, it should be returned to an envelope in this box.
  4. For daytime tests, the 50:50 dichroic is normally installed (NB on INGRID, this gives a ghost image, shifted 20 arcsec in the X direction).
  5. Check that the light path from the derotator to the dichroic, and from there to both the science cameras and the WFS, is unobstructed by e.g. mirror covers piled on the bench, bits of paper, screwdrivers.
  6. The laser (mounted overhead) should be on (indicator lamp lit). It's normally left powered on between AO runs. It takes ~ 20 mins to warm up. (If the fisba display appears not to be updating, it may be necessary to reboot the fisba PC, see the troubleshooting guide.)
  7. In the electronics room, check that the following are powered on / running normally:
    1. aocontrol1
    2. FSM (top crate of middle rack?).
    3. DM high voltage (red lamps in bottom-left corner at bottom of left-most rack). If it's not on, power on, top first, then bottom, as labelled.
    4. Hydraulic cooler (check occasionally there are no leaks from the unit, or from the pipes on and near the optical bench)
    5. WFS Peltier coolers (switch on the front of the second crate from the top of the middle rack)
    6. WFS camera controllers, and SDSU (bottom of middle rack)
    7. Mechanism control (middle rack, third and fourth crates from the bottom, and button at back of next rack up)
  8. Reboot the FISBA PC if necessary. Zoom display *3 when it comes up.
  9. Check that all lights and screen displays are off before leaving GRACE.
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At the WHT control desk

  1. Check that the air-conditioning is running (left-hand end of main control desk). Instructions for changing the fan speed can be found under the 'start point for mirror-flattening' section of this document. (Go through menu "optics - knobs")
  2. Temperature should be maintained at 10 degrees, and this is done automatically by the air conditioning. Humidity should ideally be between ~ 30 to 45 per cent (values under "optics - analogue inputs"). Large changes in temperature and humidity can invalidate any mirror flattening solution already obtained. Control humidity using the dehumidifier and humidifier in GRACE.
  3. Switch off the lights in the dome (not usually critical for setup).

At the WHT instrument-control screen (taurus)

  1. The observing system should be running, with at least AG7 (the simplex camera) available. INGRID and MIT3 may also be needed. AG3 (the acquisition camera) is needed at night. Check that the CODESO control gui came up. If you want to carry out daytime tests without being interrupted by other work on taurus (e.g. the daytime checks of other instruments), telnet to lpss94 from the right-hand lpss42 screen, login as whtobs, type obssys, answer 1 to each of next two questions, then startobssys. This will give you a copy of the OASIS-control and other guis. Note that if there are then two guis running (e.g. one on taurus, one on lpss94), whichever started first will have control of the dichroic changer and of oasis.
  2. If OSCA is to be used, check that the OSCA-control page on the NAOMI observer interface (on taurus) is present. If the NAOMI observer interface is missing, type naomiInterface & at the SYS> prompt.

At the NAOMI control screen (lpss42)

  1. Login to lpss42 (labelled AODISPLAY - SCREEN 1) as naomi. It's also useful to login to the right-hand screen. The central screen can display the naomi guis which include image displays (topgui, fisba, simplex), the right hand screen will not. [Tip for experts: if you login as root, the system will create files that then prevent further logins as naomi.]
  2. On the right-hand screen, telnet to taurus as whtobs, type obsyss , respond with 1, then 1, to bring up the TO prompt. If the OASIS server is not already started on TAURUS then type startoasisserver. Then type startoasisgui, to bring up the NCU/OASIS gui.
  3. Click on the button at the top left of the light-path gui to float the bench. NB the bench flexes slightly on floating or de-floating, causing the WFS spots to move in the y direction, by about 0.5 arcsec. After about 3 mins (floating or de-floating) the spots are within 0.1 arcsec of their final position. There is no further movement after 6 mins.
  4. Check on the light-path gui that the ADC (if present on the bench) is out of the beam. Check that nobody is physically near the ADC when it is being moved (finger safety).
  5. If OASIS is to be used, check that the mechanism labels on the OASIS engineering page of this gui are in green (none in red). Try moving a mechanism e.g. the grism wheel (unless the previous night's observer has advised against this), particularly if OASIS hasn't been used for some time.
  6. Unless the naomi top gui already appears to be up and running, type restart (or NaomiRestart) at the lpss42 prompt. (We believe that a restart is needed every 7 days or so because the SG frame count has a limit ~ 2000M, use SG Status to check it.) Type topgui & at the lpss42 prompt, to bring up the main NAOMI gui, topgui, illustrated below [fig to be annotated]:

    The 10 icons at top left:

    bring up the following pages: fisba, mechs, wfs, sdsu, c40s, light-path gui, simplex, diagnostics, real-time, DM. To see the layout of these (and other) top gui pages in more detail, click here.

  7. If the light-path gui page is not already displayed on the right hand side of the gui, click on the light-path gui icon at the top of the gui.
  8. If the scripts menu is not already displayed type AutoLauncher & at the lpss42 prompt, to bring up the scripts menu (for AutoCentre, AutoOffsets and mode configuration):

  9. Check in the NAOMI logbook (A4, usually somewhere on the control desk) the name of the last mirror-flat file, and load it, using the link two thirds of the way up the right-hand page of topgui. If it's old (weeks), it's probable better to start with the DM mid-ranged (the mid-range button is again about two thirds of the way up the light-path gui page of topgui).
  10. On the right-hand page, click to open the NGS WFS shutter.
  11. On the SDSUs page, check that the WFS CCD is reading in fast mode (slow is never used, too slow).
  12. Click on the green ring icon in the menu bar at the top of top gui to bring up the C40s page. The left ring of C40s refers to the WFS, the right ring to the SG (strain-gauge) loop for the DM.
  13. Switch on the TV above the AODISPLAYs to see the FISBA screen.
  14. Click on the button below the SG ring to close the SG loop. Check (two thirds of the way up the light path page) that the SG gain is set at 0.8. If not, type setgain 0.8 at the lpss42 prompt.
  15. The temperature of the DM can be checked with SG GetTemperature
  16. Click on the start button under the WFS ring on the C40s page, to start the WFS framing. Click on the tick box labelled 'continuous', below the bottom-left corner of the WFS display on the left-hand page, to start the display. Set the 'max' value in the window below the bottom-right corner of the display to 50. You should see WFS readout noise on the display (usually 8 counts rms), confirming that the WFS is reading out OK.
  17. Check the noise on the WFS by grabbing an image (top gui WFS page), save as fits file and displaying with iraf. Rms ~7 is OK; ~15 is not. To get to the image on disk use the alias 'cdgrab' and enter the subdirectory 'WFS' and display your image.
  18. On the light-path gui, move the NCU slide to the NAOMI simplex position. Switch on the NAOMI simplex lamp, set the simplex iris to about -150 (0 is effectively the brightest, larger values don't help, ~ -320 is faintest). Select 'edit value' if required.
  19. Check in the NAOMI logbook the on-axis position last measured for the WFS pickoff mirror (usually about 0 3, in arcsec). Set the mirror to this position, by entering the values in the pickoff x and y boxes on the right hand page of the gui, and hitting ? (alternatively, type e.g. pickoff 1 3 at the lpss42 prompt).
  20. Check on the light-path gui page that the lenslet wheel is set to 'good-seeing lenslet', that the WFS mode is set to 1, and that the tip-tilt mirror is mid-ranged (4096, 4096).
  21. Spots should now be visible in each of the boxes on the WFS display. If not, check:
    1. NCU slide is in the simplex position
    2. simplex lamp is on, with the iris (brightness) set to -150
    3. WFS shutter is open
    4. WFS exposure time is between 10 and 50 msec
    If the spots are visible but not well-centred, tweak the position of the pickoff mirror. Once the spots fall within their individual boxes, they can be centred accurately by clicking the AutoCentre button on the scripts menu (this iteratively adjusts the position of the pickoff mirror).
At this point, calibration light from the pinhole is going through the system, and is being detected by the WFS. Now check that light is being detected on the simplex camera and on the science detectors.

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Remote operation / viewing

This is a placeholder for instructions on operating the AO system from the sea-level office (3 screens on 3rd floor). [Instructions to be added.]

To see the AO displays from a linux terminal anywhere at ING or SLO:
vncviewer aodisplay1
This display s the contents of both screens (including the WFS spots), with a slider to select the area you want to see.

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Check that light reaches the simplex camera AG7, inspect PSF

  1. On topgui click on 'Simplex AG7' under 'Flattening' on the left hand side. This starts the simplex gui.
  2. On the OASIS/light-path gui, check that the OASIS flat and simplex flat are both in, so that after being reflected from the dichroic, the light is reflected from a fold flat in front of INGRID, then from another fold flat in front of OASIS, into the AG7 simplex camera. The simplest way to do this is from the OBSTOOL page of the gui - select observing mode = simplex (AG), and click on configure.
  3. Click on 'continuous' on the simplex gui.
  4. Check that the image of the pinhole is visible on the simplex display gui. The default window position is usually OK. If not, unclip it, and reset start x and y (increasing x moves the star left, increasing y moves the star up). Often the image has moved a few pixels in the vertical direction only, e.g. after floating or unfloating the bench. Use a window size ~ 30 * 30 pixels. It's usually most convenient to work with display-gui settings zoom *6, rainbow lookup table, and maximum set to the peak value (< 30000) indicated on the simplex control gui.
  5. Check the quality of the PSF (not needed on the first night of a run because you have to flatten the DM anyway):
    • From the light-path gui, set the focus to the correct value for the simplex camera, usually about 2.2 mm (see the OASIS observing recipe for latest values)
    • On the simplex gui, click 'continuous' off.
    • At the observing-system prompt, type glance ag7 0.1 .
    • Inspect the image using iraf imexam (see the section 'Check the PSF') under Simplexing , checking that:
      • The image is single-peaked, not e.g. double.
      • The FWHM is < 4 pixels, i.e there is a resonable core.
      • Most of the light falls within an area < 10 pixels across (0.3 arcsec on-sky).
      • There are less than 6 satellite spots. There should be only 4, from the central 4 segments of the DM, which are fixed.
    • If these conditions are not satisfied, or if these are pre-run or first-night checks, or if the previous night's observer has requested it, the DM must be flattened.
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Check that light reaches OASIS MIT3 (if required)

  1. Go to the OBSTOOL page on the CODESO gui, select observing mode = imaging, and spectral config = e.g. MR516. This put the OASIS flat in, takes the simplex flat out, and sets:
    1. Focal plane = clear
    2. Enlarger = clear
    3. Filter = MR516 (or whatever is requested)
    4. Imager = 62 mm
    5. Sampler = imaging lens
    6. Beam-steerer = out
    7. Grism = out
    8. Camera = -3.33 mm (never moved)
    If a wheel fails to move, with a 'duck error', repeat the request on the engineering page. The grism wheel is particularly troublesome.
  2. Set the filter focus corrector value to 2.2 mm (see OASIS observing recipe for latest values)
  3. At the taurus prompt, set up the standard CCD window, with window oasis 1 "[1:2059,1035:3140]" . The CCD can now be binned, to improve readout speed during tests.
  4. Type glance oasis 1 at the taurus prompt, display the image, check that an image of the pinhole is visible. If there's no light, check that the 50:50 dichroic is installed. If there's not enough light, or the image is saturated, change the exposure time or the simplex iris setting.

Check that light reaches INGRID (if required)

  1. On the light-path gui, set the oasis flat to INGRID.
  2. Datum the wheels, select H, clear, clear, glance INGRID 1 etc. [recipe to be added here...]
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  1. Record images of the pinhole in each band, check PSF good in all bands. Record x,y position of pinhole on science detector (useful for target acquisition).
  2. Check focus on WFS.
  3. AutoOffsets to measure the offsets of the centroids on the WFS, for each lenslet/CCD mode. It allows one to select which modes are tested. The procedure will prompt for a name for this set of offsets e.g. `test' or `ir' or `dichroic4'. Type poff (alias for PrintOffsets) to print the offsets to check that none of modes are flagged as having large offsets (if so, repeat AutoOffsets). poff ingrid prints the offsets in the file `ingrid'.
  4. Load the NAOMI reconstructor from the real-time page (second button from right at the top of top gui. Available reconstructors are: Electra (gains 105 109, pre-2003, worked fine until ~ 2007, but for some reason will no longer load properly, even though it is the 'default'), NAOMI (like Electra, but better edge performance), Sor4 (equiv to NAOMI, but doesn't work), Sor8 (new 4*4 version of Sor4, maintains planarity of each 2*2 segment in 4*4 mode, should be better for modes 8, 9, untested).
  5. Test the reconstructor closed-loop:
    • Select the required mode from the scripts menu bar.
    • Start the simplex gui, for a real-time display of the spot maximum, position and shape.
    • Arrange the windows on the screen so that you can see the spot maximum value in the simplex control gui, the simplex display and the topgui close-loop button.
    • Close the loop, check that the spot doesn't move more than ~ 1 pixel. The maximum probably *will* decrease, because the spot is no longer centred exactly on a pixel (but we believe the total flux and FWHM are unchanged).
    • Watch also what happens to the spots on the WFS. If the outer ring of spots doesn't move back to its original position, this may bea hint that the TT mirror is not working (e.g. it may be powered off).
    • Move the NCU by + 0.1 mm (0.5 arcsec), check that when the spot comes back, it is unchanged in brightness and position.
    • Select the simplex position on the NCU, which removes the 0.1-mm shift, but with a +ve jump first (hysteresis), i.e. this is a more demanding test of the loop. Check that when the spot comes back, it is unchanged in brightness and position.
    • Repeat with other modes, if desired.
    • If the outer ring of spots on the WFS shifts relative to the inner spots, check that the FSM is powered on.
    Note that after work on the software that controls the DM and FSM, the AutoTest script for testing the reconstructor for each lenslet/CCD mode no longer works.
  6. The TO needs to fill the cryostats (MIT3 + 2 on INGRID takes about 20 mins). NB during the 7/03 run we noticed temperature spikes ~ 1 deg (cooling) each time the cryostats were filled, probably associated with cold N2 gas flowing across the bench, but possibly sometimes associated with opening GRACE's double doors and letting dome air in. This may be enough to make the mirror lose shape (but then slowly recover it??).
  7. To start Craige's DM SG monitor (which shouldn't be left running during observing), click on eng guis then SG monitor. See tech info pages for documentation. Summary: Each strip represents a, b or c actuator on the segment, colour-coded according to the SG (not requested) DAC values: black = mid-range 4096, grey = elsewhere (lighter = further from 4096), red = outside specified limit. Limit is specified in bottom-right box as fraction of 4096 beyond which display goes red for that actuator. Sample interval is in sec. Temperatures always read zero (disabled, because of risk of crashing c40s).
    Snapshot = display last sampling of SG.
    FIFO = display average of last 100 samples.
    Tidemark = display greatest deviation from mid-range, since the application was started, or since the reset button was pressed.
  8. If this is the start of a NAOMI run, check the INGRID naomi-obs pupil alignment by putting in the pupil imager, with INGRID focus set to -1200.
  9. If tip-tilt mode (10) is to be used, check that mode 10 can be loaded (there are often problems switching to and from mode 10).
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  1. The Nasmyth flat should be switched to GRACE, and the TCS should be started up with the GRACE configuration, and with the autoguider switch on the control desk set to GRACE. The telescope-focus position found for the previous AO run (default 98.35, but 98.45 (12/05?) may be better) should be used.
  2. Unfloat the optical bench.
  3. Remove the cover from the GRACE derotator.
  4. Insert the required dichroic.
  5. Load the best flat found during daytime setup for the dichroic in use.
  6. If observing with OASIS, put the cap on the fisba lens, and check that the position of the OASIS focus corrector is appropriate for the filter in use (and in particular, that it's not left at the simplex value).
  7. Load the good-seeing mode 1 from the scripts menu bar. NB at 18/4/03, this states that it is loading the reconstructor, but it doesn't. The reconstructor has to have been loaded explicitly from the realtime page.
  8. AutoCheck to check parameters set correctly. E.g. decimates should be 10, 10, FSM gains should be 20, DM gain should be 0.3 for the good-seeing lenslet, 0.15 for the poor-seeing lenslet.
  9. In xterm window, NaomiAutoguider (don't type `&') to bring up the autoguider. No prompt is returned.
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  1. Slew telescope to star V ~ 9 (even better, a binary).
  2. Acquire at rotator centre on TV.
  3. Tweak position to acquire on WFS (check pickoff mirror is in correct position, as given by PrintOffsets). If the star can't easily be found, try a spiral search with the WFS pickoff mirror e.g.:
    ~naomi/bin/pickoffspiral -startx 1.3 -starty 2.4 -stepsize 1 -nospirals 4
  4. Tweak the telescope focus so that the separation of the spots is the same (8.0 pixels) as the separation of cells on the overplotted grid. Light from a star will then be focussed at the position occupied by the pinhole during simplexing. The WFS alignment tool (use described in white-light-flattening section above) is useful here, if the seeing is good and the images stable (NB the 'centroids' box below the WFS display must be ticked). For AO work, the focus doesn't have to be exactly right, the DM will correct for a small amount of defocus.
    For non-AO observations, the DM will be inactive, so it's important to focus accurately on the science detector.
  5. Make an open-loop image with a science detector or the simplex camera, exposure time > 7 sec (or e.g. coave ingrid 5, run ingrid 1 if too bright for single exposure).
  6. Start autoguiding at the TCS, with AUTO ON 50 50. If this isn't started before closing the AO loop, the autoguiding may misbehave.
  7. Set WFS exposure to 5 msec and close loop.
  8. Check in the autoguider window that packets are being sent, and check with the TO that they are being received at the TCS. Each autoguider packet is a 12-digit number. The first 4 digits are x, next 4 are y, next 4 are a flag? Check the plots of FSM x,y position vs time by clicking on the button on the diagnostics page.
  9. Switch off INGRID grab if still running, expose (from INGRID SYS> prompt), measure image FWHM at INGRID, check correction is reasonable for given natural seeing and band.
  10. If the seeing is poor, try closing loop with poor-seeng lenslet.
Back to top of page The quickest way to assess the PSF is with iraf imexam. For details, see the latter part of the section on simplexing.

Roy's strehlometer can be run with: :

  1. ~roy/bin/niit
at the unix (not lpss42) prompt. It should run equally fast at ING or SLO.

Anthony Brown's PSF tool (courtesy of Richard McDermid) can be run up with:

  1. IDL (user = oasis)
  2. .r psf_analysis
  3. psf_analysis,'file_path/',pix_scale,/plt where pix_scale is in marcsec
  4. ??? useful directories under /home/oasis/Idl/: Oasis, Psf/ (edit box size and bias level), utils
Back to top of page The instructions below refer to INGRID, but a similar procedure is required for any science detector. See the observing recipe for OASIS.
  1. Acquire guide star for science object as above. If too faint for the acquisition TV, acquire by blind offset from bright star, or put INGRID into movie mode with e.g. multglance ingrid 40 1, and acquire onto position on INGRID at which the pinhole image appeared. Make sure the NCU lamps are off. If left on, the light scattering from dust on the optical surfaces can look like a field of faint stars.
  2. Check position of science target on INGRID. If required, change position on chip by moving telescope. If telescope is moved RA" E, Dec" N, the pickoff mirror must be moved by +RA" in X, +Dec" in Y to reacquire the guide star.
  3. If required, use 'Record WFS data' button on the AutoLauncher menu, to record open-loop (not closed-loop) WFS data for Juan Carlos.
  4. Close loop as above, check autoguider signal. Tweak WFS exposure time and mode to optimise correction at science detector. E.g. if star is bright, acquire in mode 1, guide in mode 2 (quad cell) exposure time as short as 2.0 msec (as of Sep 2005). NB it's only possible to get WFS exp time = 1250 microsec if the decimate values are raised first. If star is faint, use mode 8 (4*4), integration time e.g. 50 msec. AutoCheck to check system parameters. Check correct offsets are loaded. It might be necessary to tweak the segment TT limit (up to 0.3 is OK, more than that may make the spot wander into next cell).
    There is no evidence that it takes any time for the AO correction to settle down, i.e. that it continues to improve after closing the loop.
    Spots just visible to the eye on the WFS have S:N ~ 5. NB the decimate values do *not* affect performance, just sampling for display and diagnostics.
  5. If using mode 10 (tip-tilt), the WFS display will show only 4 pixels. To check the counts, bring up the WFS page in TopGui, click on 'cursor' at the top of the page, position the cursor over displayed pixels to check their values. (NB TTdisp 0 no longer works.) The pixel values should be more than a few hundred (for reasonable S:N), but less than ~ 5000? (to avoid saturation). While the loop is closed, differences between the counts in the 4 pixels should not exceed ~ 10%. NaomiAutoguider is required, as for the other modes. For a visual check that guiding hasn't been lost, it's helpful to have the FSM X and Y traces displayed. TT mode seems to be as stable as the other modes.
  6. Take required exposures at INGRID. E.g. if dithered observation required:
  7. Closed-loop seeing is displayed just below WFS display. Integration time (in no. of samples) can be changed, see TopGui manual section Int time varies with decimation.
    dither -intcount 2 -secs 30 -skypa 0 -title "Fred" -5point 5 5
    to execute a 5-point dither, with offsets +-5 arcsec from the central position in x and y, starting from telescope nominal position with offset -3.0, 3.0 arcsec, with 2 integrations of 30 sec at each dither point. If the command e.g. coave ingrid 4 is issued, then each of the 2 integrations will be a coaverage of 4 readouts of the INGRID chip.
    Beware of starting a dither with a guide star so close enough to the edge of the available field (displayed on AG3 during acquisition) that the system will try to move the pickoff probe beyond its software limits during the dither pattern.
    The dither command works at any sky PA. NB don't type '&' at the end of the dither command.
    To break into script at a prompt, type ctrl/c then y.
    By default, the script doesn't wait at each dither point for user confirmation that the loop has closed OK. To make it wait, use switch -waitforloop on the command line.
    dither -h for help
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  1. For an observation with the loop fully open, open the loop, which reloads flat if button on C40s page is set appropriately, take an exposure.
  2. To measure the quality of the image with static correction plus tip-tilt i.e. fast-guiding ('ukirt mode'), close loop, progressively (~ 4 steps) lower SG gain to 0.00001 (and also set seg TT limit v low?) (Technique tried 9/02 was to close loop, open loop, set DM TT limit to 0.01, close loop, but this seems to suppress FSM activity rather than heighten it, reasons unknown.) To measure static correction only, i.e. no fast guiding, try setting FSM gain to zero?
  3. Reset SG TT limit.
  4. Technique for guiding only (flat mirror loaded)??
Back to top of page An open-loop offset sky is required e.g. if target large compared to dither size:
  1. WFS gui, open loop.
  2. Load last mirror flat (otherwise the DM is in the shape last demanded by the AO loop, making seeing worse, and thus exaggerating the difference between open- and closed-loop seeing).
  3. Offset telescope > 30 arcsec.
  4. Expose at INGRID.
Back to top of page Any time of night. SLODAR samples the Cn^2 contributions up to 15 km, and estimates the total contribution from higher altitudes.
  1. Login to PC, username slodar
  2. Move pickoff mirror out of the way e.g. with pickoff 60 60.
  3. Acquire binary star, ideal separation ~ 60 arcsec. Field of view is > 1 arcmin. 12*12 spots each star, so some will be on DM boundaries. Follow the SLODAR instructions. For more information, see the SLODAR page.
Back to top of page To record open-loop data from the WFS (for RM/JCG's study of AO system performance), click on 'Record WFS data' on the AutoLauncher menu, ~ 10 seconds after acquisition of the guide star. A window will pop up. When it says 'done' (a few seconds later), the process is completed. The data are saved in /data/downloads on aocontrol1. NB currently only open-loop data are useful, not closed-loop. Back to top of page Instructions from SMT 29/4/05:
first setup your window as normal. Then type at the SYS prompt : 'rsrun AG7 X Y' where X= number of expsoures required, Y= expsoure time required. Since the chip is not cleared between exposures (true FT operation) the actual exposure time is the demanded time+readout time. You therefore need to set Y to zero for the quoted speeds. X has a max value of 127 although it could be easily extended by Richard Bassom. I have tested it up to 3000 frames with QUCAM1 but the cycle time gradually slows down as the memory of the sparc fills up. With smaller windows it may not be such a problem but you would need to test it. The file format is that each rsrun frame is stored as a fits extension [1]..[127] in the same file. We occasionally receive requests for short non-AO target-of-opportunity observations with INGRID, e.g. to catch the IR afterglow of an impact on a solar-system object.

With the DM in the light path, such an observation will deliver a seeing-limited PSF only if the DM has been flattened beforehand. This is labour-intensive, and the shape of the DM may not be stable for long periods, which could be a problem e.g. for a time-critical observation required over the weekend, when nobody is available to flatten the DM.

One way around this is to mount over the DM the flat (lambda/8) circular mirror purchased some years ago by Tom Gregory. This then substitutes for the DM in the light path.

The mirror should be mounted over the DM only by an ING optical engineer or by someone they explicitly authorise to mount it, after suitable training. The procedure is as follows:

  • The mirror lives in a box labelled something like 'Flat mirror to go over DM' in the left-most GRACE/GHRIL cupboard on the Nasmyth level.
  • Remove the mirror from the box. The frame has 4 holes, so it can be pushed over the 4 posts protruding from the DM frame. The up-down orientation is probably not important.
  • The mirror can then be positioned over the DM in two possible ways: with the mirror very close to the DM, or, flipping by 180 deg, with the mirror well away from the DM. You want the former, i.e. mirror surface lying only a couple of mm in front of the DM. Be very careful not to touch the DM surface.
  • Once the mirror is in place, screw retaining nuts onto the posts until they are just finger tight. Do not over-tighten.
The mirror is in a near-parellel beam, so should deliver a sharp image of the simplex pinhole on INGRID. In fact, the image is a symmeticrical doughnut, clearly out of focus. The reason for this is unknown, but it should be possible to take out this defocus by refocusing the telescope e.g. on a star V ~ 10 (?) mag. This hasn't yet been tried on-sky. No other means of refocusing is available apart from either physically moving INGRID, or moving INGRID's internal focus mechanism, which has been powered off to avoid it jamming (?).

Things to bear in mind when arranging for such an observation to take place:

  • The optics covers need to be removed from each component along the light path by the daytime staff, the flat mirror should be installed, the IR dichroic should be used, INGRID should be configured with the correct filters and pupil stop, INGRID should be visible to the observing system.
  • The proposer needs to be aware that the observation will be unguided (the WFS will see spots, but the loop will probably not be running).
  • Agreement needs to be reached with the OSA for the night, and the OSA's line manager, that they can carry out the observation required, and explicit step-by-step instructions should be provided. These instructions should include guidance about how to focus the telescope on INGRID, and what exposure times and dither pattern are needed.
As of June 2010, this mode of observing has yet to be tested on-sky.
  1. In GRACE, move the metal slide below the front of the WFS camera. It has 4 positions (see label on top of WFS box). The slide is fairly stiff. It seems to click firmly into place, but if the WFS display looks odd, try moving it out and back in again.
  2. In the electronics room, switch off the FSM controller.
  3. In GRACE, open the door giving access to the back of the electronic racks. Switch from CCD39 to L3 or vice versa (well-labelled switch on small box close to the FSM control rack).
  4. In the electronics room, switch on the FSM controller.
  5. Noise from the either controller can cause noise (e.g. horizontal banding on the other) so if the L3 is in use, switch off the CCD39 controller, and vice versa.
  6. Change the WFS camera-stage focus to 165 for the L3 camera, or 210 for the CCD39.
  1. Switch of all lamps in the NCU, from the light-path gui.
  2. Make sure the AO loop is open (button on the default top-gui page).
  3. Unfloat ('fix') the table, from the button on the light-path gui.
  4. Park the dichroic, (1) to protect from dust and (2) because if it's left clamped for a long period, some tilt can build up (drop in pneumatic pressure).
  5. Stop framing of WFS and simplex cameras.
  6. Check that air-conditioning was reset to 100% after setup!
  7. Blank filter in INGRID
  8. Turn focal-plane wheel in OASIS to 'shutter', to protect the optics from dust.
  9. Mid-range DM to minimise strain, open SG loop, or SG SetGain 0.00001 and leave closed.
  10. ctrl/c to stop autoguider signal.
  11. Close WFS shutter (as of 12/06, seems to be working OK)
  12. In GRACE, put caps on OAP1, OAP2, DM, main fold flat, laser and laser flat, put pinhole in ready for next day (if flat-fields not required during day). Make sure the doors in GRACE are closed properly. Tape a piece of paper over the NCU aperture facing the derotator (below AG3), to keep dust off the AG3 field lens.
  13. Fisba should be switched off if their is a long interval (more than a few days?) before the next run.
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Commands to issue at any unix prompt:

  • aoperf or ~roy/bin/niit? (to run Roy's strehl meter)
  • xgterm &, then cd, then cl within the xgterm window, to start iraf

Commands to issue at the WHT instrument control SYS prompt:

  • coave ingrid 5 (each exposure read to disk is average of 5 exposures)
  • dither -intcount 2 -secs 30 -skypa 0 -title "Fred" -5point 5 5 (or -9point)
  • mimic (starts Craige's NAOMI mimic)
  • obssys - start observing system (useful to run up oasisgui)
  • run mit3 7 "NGC 1234" & (MIT3 exposure)
  • run ingrid 7 "NGC 1234" & (INGRID exposure) (alternatives to run: glance, scratch, flat, sky, arc, pupil)
  • setoasis - sets up MIT3 with standard windows, speed and binning
  • startobssys
  • startoasisserver, then startoasisgui - bring up the CODESO gui
  • window oasis 1 "[1:2059,1035:3140]" - set standard window on MIT3

Commands given at the lpss42 prompt (the aliases are listed in .aliases):

  • AutoCheck - check the parameters have been set correctly for this configuration
  • AutoLauncher & - launch Auto menu
  • AutoRectifyFlat - tries to cure mirror after a slopes event, by tilting each segment to put the WFS spot at correct offset (pinhole in, flat on, tries to autocentre, zeroes reconstructor, closes loop, opens loop, grabs DACs...
  • AutoUpdateOffests - update offsets for a particular configuration e.g. g1, without having to do all the configurations (same as AutoOffsetsNew edit?)
  • AutoWhite - do white-light flat
  • cdflat - change to flats directory
  • cdgrab - change to grabs directory
  • cdpeak - change to current directory for wlflat results
  • --camera AG7 & - bring up simplex gui
  • mplot - run crb's mplot program to plot mirror flats
  • NaomiAutoguider - start autoguider (don't type '&')
  • pickoff 0.0 3.0 - moves the pickoff mirror to x = 0.0", y = 3.0"
  • pickoffspiral -startx 1.3 -starty 2.4 -stepsize 1 -nospirals 4
  • plotflathist 20050512-122625.white - plot out the flat
  • poff (= PrintOffsets) - list current offsets
  • restart (= NaomiRestart) - resarts everything.
  • setgain 0.8 - sets SG gain to the default value
  • stairx 40, stairy 40 - add staircase to DM
  • topgui & (= TopGui &) - starts the top-level eng gui)
  • TTdisp 0 - start the continuous display of pixel values for mode 10
  • ? to run off DM temperature log

Commands given at the aocontrol1 prompt:

Commands given at the iraf prompt:

  • !ds9 - start ds9 image display
  • display s1[1] 1 fil+; imexa - display glance image, start imexam
  • imexa - start imexam analysis tool

Commands given at the TCS prompt:

  • AUTO ON 50 50 - required prior to starting autoguiding
From Richard Myers (20/7/03):

>Temporary Documention for WFS Offset Configurations
>WFS "configs" (configurations) are a means of managing multiple
>sets of flat plus WFS offset combinations. For example,
>different dichroics may need a different simplex, hence
>a different flat file, and therefre a different set of offsets.
>Configs allow one to associate a config name with each
>such set of offsets. The config name may then be used to retrieve
>NOTE: the configuration system is implemented in the NAOMI
>"Auto" script system. This whole system is temporary and has
>been integrated into TopGui (along with offset management). It will be
>commissioned at the next major release.
>Modified Commands:
>AutoConfig WFSmode [config]
>	   now has a new optional config parameter allowing one
>	   to specify a particular set of of offsets to retrieve
>	   the requested WFSmode settings from. 
>	   e.g. AutoConfig g1 oasis1
>	   this will retrieve the g1 settings assoicated with the
>	   oasis1 config.
>	   You can still use the default (e.g., Autoconfig g1)
>	   and get the g1 settings from the latest set of offsets
>	   taken.
>AutoOffsets [noedit]
>	   now defaults to edit mode and subsumes all features
>	   of AutoOffsetsVeryNewSelect (selectable integration times
>	   and g11, g12 modes). The edit parameter no longer has
>	   any meaning and should NOT be used.
>	   AutoOffsets now asks the user if the new offsets should
>	   be merged with an existing config. If merging
>	   is required then the user is a given a list of configs
>	   to chose from. If merging is not required then the
>	   user is prompted for a name for the new config. (e.g.
>           oasis2).
>	   OVERRIDEN (this is assumed to be the most convenient
>	   behaviour for working with dichroic simplexes).	
>AutoRectifyFlat [config]
>           can now attempt to restore the segment tilts associated
>           with the g1 mode of a given config rather than
>	   the g1 mode of the last set of offsets (the default).
>PrintOffsets [config]
>	   can now print a summary of offset settings associated
>	   with the specifed config rather than the last set of 
>           offsets (default).
>	   print the configs and associated schedule (index) files.   
>           Schedule files contain pointers to the flat and offset 
>           files for each WFSmode (g1, etc) (for which offsets have 
>           been taken).
>AssignSchedule [schedule [config]]
>	   allows you to associate a config with an old schedule
>	   (.index) file which did not have one, or to reinstate a 
>           schedule whose previously associated config has been 
>           overridden.
>PrintSchedule [schedule] 
>	   still works at the schedule (index) file level and ignores 
>           configs
>MergeSchedule [schedule1] [schedule2]
           Merges old and new offset files?
>	   still works at the schedule (index) file level but
>	   prompts the user for a config name for the merged 
>           schedule.

Data Example
Mirror flats $flats = /software/Electra/save/flat/20010630-1033
WFS offsets /software/Electra/save/WFScentroidOffsets/20000917-032706.wcnof
Grabs /software/Electra/save/Grabs/WFS/20000908-113032.fits
Inteferometry ~naomi/WhiteLight/20010830/20010830.131527.scanH .scanV .peakH .peakV
The interferometry files are recorded in the current (usually home) directory.

Machine names:
Name Address Function NAOMI control (NAomi VISualisation)
aocontrol1161.72.6.127 WFS data-processing, DM control Mechanism control, via vxWorks SDSU control, via vxWorks Fisba-interferometer control
scorpio commonly-used machine in main unix cluster
ra1 only unix-cluster machine permitting external access

Machine Username
lpss42 naomi (this account doesn't work on the main unix cluster)
SBIGPC1/2 sbig

C40s Processors running the WFS and SG loops
DAC Digital-to-analogue converter units
DM Deformable mirror
FISBA FISBA double-pass interferometer
FSM Fast-steering mirror (= tip-tilt mirror = OAP1)
NCU Nasmyth calibration unit (lamps, acquisition camera)
OAP1 Off-axis paraboloid 1 (= FSM)
OAP2 Off-axis paraboloid 2
OMC Opto-mechanical chassis
SG Strain gauge (for DM hysteresis correction)
TCS Telescope-control system
USP Universal science port - actually a collection of mechanisms added to allow use of OASIS.
WFS Wavefront sensor

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Contact:  (NAOMI Instrument Specialist)
Last modified: 22 October 2011