Subject: APO User's committee meeting, 3/10/03

From: strauss@astro.Princeton.EDU

Submitted: Fri, 14 Mar 2003 13:35:47 -0500 (EST)

Message number: 659 (previous: 658, next: 660 up: Index)

  Apache Point Observatory 3.5m User's Committee Meeting
		March 10, 2003

Attending: Bruce Gillespie, Ed Turner, Michael Strauss, Alan Uomoto,
Rene Walterbos, Jon Morse, Al Harper, Bruce Balick, Russet
McMillan, Chris Stubbs


Russet McMillan: In a recent experiment during an engineering night,
the Shack-Hartmann camera was operated in frame-grabbing mode with the
telescope pointed into, 30 degrees from, and away from a strong wind
(gusts to 30 mph).  Movies of the results can be found at: 
 Each of these movies give you 30 frames per second over a total of 90
seconds.  The jitter is substantial (2.5" 30 degrees from the wind, 4"
into the wind), unless you look well away from the wind, in which
case, the effective seeing is sub-arcsecond.

  There is some disagreement whether this is due just to shaking of
the secondary truss, or whether the primary is also involved.  Chris
Stubbs points out that the secondary windshake used to be even worse,
until we stiffened the braces at the top end some time ago. 

  The next thing to do is to see what things look like under calmer
conditions.  We will soon have the ability to do this with 100 Hz
frame rate.  This will give us the ability to look at image motion at
frequencies up to 50 hz, and hopefully isolate (and remove) harmonic
image jitter that is telescope-induced or resonant.

********CIF plans for 2003
Ed Turner and Bruce Gillespie announced those projects to receive CIF
funding for 2003; these reflect the recommendation from the community
not to spread our resources too thin.

In the general sense, the CIF plan for 2003 focuses on completion of 
several projects already underway, and reflects an elevated priority 
in keeping the telescope working in a reliable manner, plus fixing 
known problems in the optics support systems and improving imaging 
performance.  About half of the CIF budget will be spent completing 
2002 leftover commitments, and at mid-year the balance will be split 
between telescope improvement projects and new instrumentation; the 
exact split is TBD depending on the outcome of various funding 
proposals for the new instrumentation.

Projects leftover from 2002 (to be completed mid-2002)

  Baffling:  Construction and installation of the tertiary baffle, 
  2ndary and Nasmyth baffles plus the "cat-eye" baffle for the primary 

  DIS optics upgrade:  Finishing the red-side upgrade in April

  Remote s/w upgrade:  Complete by June.

  Echelle guide camera:  Finish the guide camera upgrade, and work on 
  echelle detector upgrade proposal.

Telescope improvements (to be completed by end of 2002)

   Optics supports/motion control:  Complete planning, testing, designs 
   and some implementations to improve telescope image quality and 
   reduce image jitter.  Also provide better safeties for mirror motions.


   Complete detector upgrade, acquire critical spare parts, acquire 
   add'l filters, hold final review.

JHU/Chicago Spectrograph

  If NSF proposal successful, instrument will be built.  If so, some 
  compensation from CIF to UChicago will be required.

************News from DIS
  The red camera will be upgraded to minimize vignetting and improve
the pixel scale, during the April bright run.  
  Rene Walterbos: There is substantial scattered light on the blue
camera; the spectrum of a standard star shows wings that extend out to
30 arcsec.  Spectra of a planetary nebula show no appreciable smearing in
the wavelength direction, so it sounds like something that is
happening upstream of the camera itself.  This should be checked by
taking images with DIS, which can easily be done in twilight.  
  There is discussion about implementing a "nod and shuffle" observing
mode for faint-object spectroscopy, which is supposed to much improve
sky subtraction in the red.  This requires some software upgrades,
which is in the plate of Craig Loomis and Russell Owen.  Their hands
are full with the upgrade to the whole observing interface, which we
all agreed was higher priority.  There is apparently some real success
with this procedure at Gemini, and John Morse referred to a URL that
describes this; John, could you tell us this URL? 

***********Telescope baffling report

  Metal is being cut; hooray!  We're about to take delivery of the
tertiary cone baffle, to be installed in April.  This should improve
the scattered light quite a bit, although it is not the full job
(which includes both primary and secondary baffles as well; they are
longer-term items)

***********NIC-FPS report

  Jon Morse: There is a review coming up on April 4 which will focus
on integration and testing. All the pieces for the vacuum housing
should be in place by that time; the optics should be delivered and
tested around that time.  The background materials for the review will
be posted to the NIC-FPS web page beforehand.

  John expects to receive an engineering-grade chip plus drive
electronics by mid-April. 

***********2003 engineering and shutdown plans
  Thre will be a 5-day shutdown during the May bright time for shutter
door/enclosure repairs.   The summer shutdown will extend from July 7
through August 15.  Mark Klaene has generated a task list:

  Wash M1, Recoat M3, Service M2 and M3 actuators, Modify M2 
  mount for larger flex pivots, Rebuild Altitude axis drive assembly, 
  Service rotator bearing/drive

  Other possible work: Replace shutter camrol bearings, PMSS component upgrades

  Even with the drive failure last November, we decided not to go with the
direct drive system a la the SDSS telescope, but just make sure that
we have a proper set of spares. 

************Mt. Stromlo support

Ed Turner reports that he is giving a few nights of Director's
Discretionary time to a student of Ken Freeman to use the echelle to
finish observations for her thesis, which was cut short sadly by the
devastating fire.

**********apo35-general usage & policy
  There are quite a few observers who do not subscribe to the
apo35-general mailing list.  As this is the principal mechanism for
communication with the user community, this is not a good thing.
Michael Strauss has made up the full list of people trained to use the
telescope who are not on the mailing list, and has distributed it to
the user's committee to track down the miscreants. 

  Bruce Gillespie mentioned several projects in progress.  There is
increasing interest in the possibility of using the echelle for
accurate radial velocity work for extrasolar planet searches.  There
is a prototype dispersed Fourier Transform Spectrograph from USNO
which should be able to measure radial velocities for stars with
meter/sec accuracy.  Tom Murphy and Chris Stubbs are installing a
laser lunar-ranging system, which should see first light this summer.
And the ARC Board of Governors are meeting at APO in June to discuss
the future of the observatory, SDSS, and everything.

  Last month's meeting minutes were approved.  
  The next meeting will be held Monday, April 14, at 11:30 Eastern

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