Subject: APO User's Committee meeting minutes, 07/04/03

From: Michael Strauss

Submitted: Thu, 7 Aug 2003 12:01:32 -0400

Message number: 687 (previous: 686, next: 688 up: Index)

	APO 3.5m User's Committee Phone Conference
		    August 4, 2003

Attending: Ed Turner, Alan Uomoto, Bruce Gillespie, Mike Shull,
Michael Strauss, Russet McMillan, Russell Owen, Karl Glazebrook, Jon
Holtzman, Al Harper, Chris Stubbs

Absent: Don York, Bruce Balick, Rene Walterbos

Status of summer shutdown
The Telescope User Interface 
Telescope focus responsibility
News on instruments, etc. 

  Gillespie: The following are highlights among the many tasks being done:
     Tertiary has been realuminized.
     John Barentine has been working on NIC-FPS at Colorado
     Craig Loomis and Russ Owen have been working on TUI (see below)
     Two of the three DIS grating tilt motors have been replaced (they were missing and adding steps)
     The primary has been washed 
     Work is on-going on the primary mirror supports and the secondary actuators
     Work is on-going to rebuild the telescope drives, including the
       rotator.  The rotator now much smoother than before. 

     It will take an extra week to put it all together, mostly because
of the drives, so some observers will lose telescope time.  Restarting
on the sky always takes a night or two of engineering on the sky, so
it will depend on the weather in late August.  It has been quite a dry
summer (bad news for forest fires); the monsoon has not yet begun... 

  Given the on-going problems with the telescope drives, it was
suggested that we have two sets of them, so that one is always
available as a spare.  This has been considered; it would cost an
estimated extra $120,000 to do so.  It is not high enough priority on
the CIF budget at the moment.  We are seriously looking at redesigning
and replacing the drive boxes, including having five built (3 in
service and two as spares).  In-house estimates of the total cost are
in the $50-100K range. 

  Mike Carr of Princeton came out to the site and gave DIS a
mechanical once-over, and said it looks in very good shape (other than
the grating tilt motor change mentioned above. 

  A small number of new cracks in the hex-cell ribs primary mirror,
which were not present two years ago, have been seen.  The good news
is that they are few and tiny, and the old cracks have have not grown
at all in several years.  These new cracks show up where spreader bars
are glued onto the sides of the hex cells.  They are probably a
consequence of the original epoxy glueing job.  To fix these would
involve substantial risk, downtime, and expense.  We will continue to
watch and hope that things don't get worse....

***********Telescope-User Interface (TUI)**********

  This is the new Python-based replacement for Remark that Loomis and
Owen are developing.  They have been working particularly hard over
the shutdown.  As reported earlier, this will require that each ARC
institution have a modern version of Python installed at their site.
Seethe web site for details. 

At the moment, one can use TUI to take exposures with the echelle,
DIS, and GRIM, and set the DIS configuration.  On the task list are: 
		 -Image display
		 -Widgets for focus
		 -User catalogs of objects
		 -Echelle and GRIM configurations
		 -SPICAM exposures (should be easy)

  Note that the SPICAM command-line interface will still exist. 
TUI will support scripting, and should allow us to use the DIS slit
viewer and the guide camera as well.  

***********Telescope focus: who's responsible?

  There has been a fair amount of confusion and controversy over the
question of who is responsible, the observer or the Observing
Specialist (OS) to keep an eye on the telescope focus, and to correct
it if necessary.  This debate arose after some unfortunate recent
incidents (under unusual conditions of rapid temperature changes, I
believe) in which data were taken with the telescope delivering

  Russet McMillan says that the OS should have a large chunk of the
responsibility of keeping an eye on the focus, but admitted that all
the OS don't necessarily agree with her.  The OS has the advantage of
access to the guider images, which the remote observer can't easily
access (soon to change with TUI; see above!).  
  Jon Holtzman emphasizes that the ultimate responsibility is with the
observer; they are the ones who are responsible for the scientific
quality of the data.  Having said this, getting input from the
observing specialist is definitely very welcome! 
  Chris Stubbs articulated three issues in the debate: 
     The responsibility for the scientific integrity of the data rests
       with the astronomer, with information from the OS. 
     We need to make sure that all OS are clear on how to
	monitor focus, and that there is a common set of
	well-communicated expectations.  
     Clarity: Where do these responsibilities reside?  Are the OS
actually responsible for monitoring the focus, even if the observer
has the responsibility to declare that we need to refocus?  
  All agreed that if the OS notices that the focus appears soft, this
should be communicated to the obserer.  

  There are programs where very high-quality focus is a premium, in
which case there needs to be communication between the observer and OS
to this effect.  

  A solution: some sort of autofocus?  Use information from slit
viewer/guider together with IDL code to determine the error in the
focus, and use it to suggest a new focus.  We discussed different ways
that this might be implemented.  
Russet: A consensus:  
   -Let's improve communication between OS and observers.   
   -A certain amount of responsibility of monitoring image quality
     lies with the OS. 
   -But overall responsibility of the image quality lies with the

Needless to say, this will be the subject of further discussion to
clarify this and other issues of OS vs. astronomer responsibility.  If
you have thoughts/input, please talk with your User Community

*********************News on instruments************************

There is good news and bad news from the NSF.  The good news is that
the proposal to fund various aspects of NIC-FPS was approved.  The bad
news is that the proposal to fund the near-IR spectrograph to be built
at JHU was not successful.  The worse news is that Alan Uomoto is
leaving us (and JHU) to take a new position with the Magellan project
in Pasadena.  We wish him the best of luck, and will miss him.  

  Mike Shull reported that NIC-FPS is progressing well, with Jim Green
now as PI.  They are now working on integrating the optics and testing
the dewar. 

  Last month's minutes are approved. 

  Next meeting, September 15, 11:30 AM Eastern time.  

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