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 (crb@ing.iac.es)
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.
Checks:
- 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.
- 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.
- 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).
- 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.
- 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).
- 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.
- 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.)
- In the electronics room, check that the following are
powered on / running normally:
- aocontrol1
- FSM (top crate of middle rack?).
- 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.
- Hydraulic cooler (check occasionally
there are no leaks from the unit,
or from the pipes on and near the optical bench)
- WFS Peltier coolers (switch on the front of the second
crate from the top of the middle rack)
- WFS camera controllers, and SDSU (bottom of middle rack)
- Mechanism control (middle rack, third and fourth crates
from the bottom, and button at back of next rack up)
- Reboot the FISBA PC if necessary. Zoom display *3 when it comes up.
- Check that all lights and screen displays are off before
leaving GRACE.
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- 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")
- 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.
- Switch off the lights in the dome (not usually critical for setup).
- 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.
- 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.
- 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.]
- 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.
- 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.
- 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).
- 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.
- 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.
- 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.
- 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):
- 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).
- On the right-hand page, click to open the NGS WFS shutter.
- On the SDSUs page, check that the WFS CCD is reading in fast mode
(slow is never used, too slow).
- 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.
- Switch on the TV above the AODISPLAYs to see the FISBA screen.
- 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.
- The temperature of the DM can be checked with SG
GetTemperature
-
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.
- 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.
- 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.
- 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).
- 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).
- Spots should now be visible in each of the boxes on the
WFS display. If not, check:
- NCU slide is in the simplex position
- simplex lamp is on, with the iris (brightness) set to -150
- WFS shutter is open
- 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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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.
Back to top of page
- On topgui click on 'Simplex AG7' under 'Flattening' on the left hand side.
This starts the simplex gui.
- 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.
- Click on 'continuous' on the simplex gui.
- 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.
- 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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- 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:
- Focal plane = clear
- Enlarger = clear
- Filter = MR516 (or whatever is requested)
- Imager = 62 mm
- Sampler = imaging lens
- Beam-steerer = out
- Grism = out
- 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.
- Set the filter focus corrector value to 2.2 mm (see OASIS observing
recipe for latest values)
- 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.
- 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.
- On the light-path gui, set the oasis flat to INGRID.
- Datum the wheels, select H, clear, clear, glance INGRID 1 etc.
[recipe to be added here...]
Back to top of page
- 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).
- Check focus on WFS.
- 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'.
- 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).
- 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.
- 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??).
- 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.
- 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.
- 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).
Back to top of page
- 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.
- Unfloat the optical bench.
- Remove the cover from the GRACE derotator.
- Insert the required dichroic.
- Load the best flat found during daytime setup for the dichroic
in use.
- 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).
- 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.
- 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.
- In xterm window, NaomiAutoguider (don't type `&')
to bring up the autoguider.
No prompt is returned.
Back to top of page
- Slew telescope to star V ~ 9 (even better, a binary).
- Acquire at rotator centre on TV.
- 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
- 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.
- 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).
- Start autoguiding at the TCS, with AUTO ON 50 50. If this isn't
started before closing the AO loop, the autoguiding may
misbehave.
- Set WFS exposure to 5 msec and close loop.
- 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.
- 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.
- 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: :
- ~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:
- IDL (user = oasis)
- .r psf_analysis
- psf_analysis,'file_path/file.fit',pix_scale,/plt
where pix_scale is in marcsec
- ??? useful directories under /home/oasis/Idl/: Oasis,
Psf/psf_analysis.pro (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.
- 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.
- 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.
- If required, use 'Record WFS data' button on the AutoLauncher
menu, to record open-loop (not closed-loop) WFS data for
Juan Carlos.
- 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.
- 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.
- Take required exposures at INGRID. E.g. if dithered observation
required:
- Closed-loop seeing is displayed just below WFS display.
Integration time (in no. of samples) can be changed, see TopGui
manual section 6.6.4.1.3. 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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- 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.
- 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?
- Reset SG TT limit.
- Technique for guiding only (flat mirror loaded)??
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An open-loop offset sky is
required e.g. if target large compared to dither
size:
- WFS gui, open loop.
- 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).
- Offset telescope > 30 arcsec.
- Expose at INGRID.
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Any time of night. SLODAR samples the Cn^2 contributions up to 15 km,
and estimates the total contribution from higher altitudes.
- Login to PC, username slodar
- Move pickoff mirror out of the way e.g. with pickoff 60 60.
- 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.
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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.
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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.
- 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.
- In the electronics room, switch off the FSM controller.
- 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).
- In the electronics room, switch on the FSM controller.
- 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.
- Change the WFS camera-stage focus to 165 for the L3 camera, or
210 for the CCD39.
- Switch of all lamps in the NCU, from the light-path gui.
- Make sure the AO loop is open (button on the default top-gui
page).
- Unfloat ('fix') the table, from the button on the light-path gui.
- 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).
- Stop framing of WFS and simplex cameras.
- Check that air-conditioning was reset to 100% after setup!
- Blank filter in INGRID
- Turn focal-plane wheel in OASIS to 'shutter', to protect the optics
from dust.
- Mid-range DM to minimise strain, open SG loop, or
SG SetGain 0.00001 and leave closed.
- ctrl/c to stop autoguider signal.
- Close WFS shutter (as of 12/06, seems to be working OK)
- 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.
- Fisba should be switched off if their is a long interval (more than
a few days?) before the next run.
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*** IN PREPARATION ***
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
- IngrdiAlign.py --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
>them.
>
>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).
> IF AN EXISTING NAME IS GIVEN THEN THE EXISTING CONFIG IS
> 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).
>
>
>NEW COMMANDS:
>
>PrintConfigs
> 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.
>
>
>OTHER NOTES
>
>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.
>
Filenames:
| 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
|
| lpss42.ing.iac.es | 161.72.6.126 | NAOMI control (NAomi VISualisation)
|
| aocontrol1 | 161.72.6.127 | WFS data-processing, DM control
|
| naomiomc.ing.iac.es | 161.72.6.129 | Mechanism control, via vxWorks
|
| naomisdsu.ing.iac.es | 161.72.6.128 | SDSU control, via vxWorks
|
| fisba.ing.iac.es | 161.72.6.133 | Fisba-interferometer control
|
| scorpio | 161.72.6.22 | commonly-used machine in main unix cluster
|
| ra1 | 161.72.6.56 | only unix-cluster machine permitting external
access
|
Usernames:
| 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 |
| | |
|
