Subject: 3.5-m Users Committee minutes 5/01/06

From: Bruce Gillespie

Submitted: Fri, 5 May 2006 10:20:17 -0600

Message number: 963 (previous: 962, next: 964 up: Index)

                         APO 3.5-m Users Committee Phonecon, 5/01/06

Attending:  Suzanne Hawley, Bruce Gillespie, Jon Holtzman, Remy  
Indebetouw, Michael Strauss, John Wilson, John Bally, Bruce Balick,  
Don York, Karl Glazebrook

Absent: Al Harper, Russet McMillan

Minutes taken by Bruce Gillespie


User feedback, comments from institutional representatives:

Princeton (Michael Strauss):  The Princeton users are happy.  As to  
the Target-of-Opportunity questions posed at the last meeting,  
Michael said there is strong PU support for the idea of promoting ToO  
use of the telescope--it's what the 3.5-m telescope excels at, plays  
to our strength, but that ToO programs should be vetted and held to  
the same science standards as regular observing programs.  Suzanne  
added that unplanned last-minute ToO proposals will be considered  
without a written proposal, but in these cases she expects one to be  
submitted rapidly (within 1-2 days) if the ToO program will be  
ongoing.  Such proposals need to submitted through the institutional  
scheduler as discussed at the last users committee meeting.

Colorado (John Bally):  No CU user feedback to report, and John also  
feels strongly that ToO programs should be supported.

NMSU (John Holtzman):  Nothing to report from users or on the ToO  

Johns Hopkins (Karl Glazebrook):  Only complaint is about the weather  
[editor's comment: JHU observers must have been unlucky recently],  
and Karl said he got no user response to the ToO issue.

Chicago: (Don York for Al Harper):  Don said that the UC faculty  
strongly supports ToO use of the telescope, and he also agrees that a  
proposal and review should be required for ToO programs.

UWashington (Bruce Balick): Nothing to report from the UW users.

Univ. of Virginia (Remy Indebetouw): UVa users are generally happy,  
but Remy has received no user feedback to the ToO questions.


Discussion of telescope/instruments report:

BruceG summarized highlights from the report (see below).  BruceG  
also mentioned that there was an accident on the APO road last week  
where two electric company linemen were killed in a fall while  
attempting to replace a defective power pole.  Several staff members  
from APO and NSO/Sunspot were first responders at the accident scene,  
and the deaths of two young men, both from Cloudcroft, is a terrible  
tragedy for the community.


      3.5-m Telescope, Instruments, and CIF Projects Highlights,  
3/30/06 through 4/27/06

                                  Bruce Gillespie

0) Overview

Highlights include continued dry conditions at the site (good for  
observing, bad for forest-fire risk), a well-behaved telescope and  
instruments, good progress on the new top-end and DIS-upgrade projects.

1) Telescope

The 3.5-m telescope was again largely well behaved during the past  
month and on the sky nearly every night.  An investigation into why  
we occasionally see slightly elongated images has suggested a problem  
with one of the tertiary mirror actuators.  Replacing a suspect  
encoder did not solve the problem, and we believe that the tertiary  
will need to be removed to find the root cause, which is probably a  
damaged flex pivot.  In the meantime, we have turned off the servo  
that does fine alignment of the tertiary, in an attempt to eliminate  
residual image wander at the expense of slightly degrading pointing  
accuracy.  Also, a new version of the TCC software was installed and  
tested, a pointing model was made, and a method to improve the speed  
of computed telescope offsets was successfully tested.  Lastly, there  
was in unexplained sudden occurrence of a telescope pointing glitch  
of a few arcminutes--this was corrected for in a subsequent pointing  
model, but the root cause remains a mystery.

2) Instruments

The performance of all the instruments was generally good.   
Noteworthy was the installation and successful testing of a new  
control computer for SPIcam.

3) Engineering and CIF projects

Design and fabrication work continued on the new top end, and the  
project remains on track.  The DIS upgrade project (gratings, optics,  
new detector) continued; parts are being ordered and components are  
being machined, and a schedule for their installation was drafted.   
The new red detector has still not been delivered from e2v.

4) Miscellaneous

The dryness, wind, and onset of the pine-pollen season has elevated  
the dust/particulate levels at APO to nearly double the normal  
levels.  We are liquid-CO2 cleaning the telescope optics several  
times a week (which has resulted in LC02 shortages from our vendor)  
in an attempt to keep the telescope on the sky as much as practical.   
We have completed the fire-protection enhancements to the site,  
including outside water sprinklers, tree removals, a fire truck on  
station, leak repairs to our water-storage tank, and the installation  
of exterior metal shutters on building windows.


DIS upgrade plans - Hawley, Holtzman:

JonH reported that it's time that the users became aware of the soon- 
to-happen upgrades to DIS.  In mid-June, two new grating and mounting  
assemblies will be installed.  On both the red and blue sides of the  
instrument, the medium and low gratings are being replaced with new  
medium gratings that we hope become the "standard" for low/medium  
resolution.  The blue-high grating is not being changed, but a new  
red-high grating is being added sometime later to replace/supplement  
the existing red-high.  All the old gratings can be swapped back into  
DIS on request, but this should be done sparingly, if at all, because  
the new gratings should give better overall performance if they work  
as advertised.

Jon said he'd post a fact sheet about the new gratings shortly so  
that users can learn what the changes will be.  Later in June, we  
plan to install a new prism into the blue side of the spectrograph to  
recover UV sensitivity (hopefully to the atmospheric cutoff), and  
replace the red detector with a thick-substrate version that should  
reduce or eliminate the red-fringing problem.


Visiting instrument proposal - Hawley:

Suzanne reported that we have received a proposal from a non-ARC  
astronomer to build a wide-field NIR camera and grism spectrometer  
with a 15-arcminute FOV and a programmable slit mask, and bring the  
instrument to the 3.5-m for their and our use.  This would be in  
exchange for telescope time much like the arrangements we currently  
have for CorMASS and the Goddard Fabry-Perot instruments.  Several of  
the Users Committee members expressed strong support for continuing  
to pursue this initiative, and commented on how such an instrument  
would complement NIC-FPS and further our interests in general NIR  
science capabilities.

ACTION: Suzanne asked each Users Committee member to send her a  
paragraph or two in the next two days with an expression of interest  
and/or questions regarding this proposed NIR instrument.


Futures Committee news - York:

Don will send BruceG copies of two Futures Committee documents that  
will be forwarded to the Users Committee members, who are then to  
help their institutional Futures Committee member share them with  
their constituent faculties and collect feedback.  Don reported that  
the Futures Committee report will recommend that the 3.5-m telescope  
continue to be operated after 2008 much the same as now, with new  
instruments, remote observing, CIF funding at current levels, and  
with no general repurposing needed to remain viable and productive.   
For the 2.5-m telescope, there is now a substantial list of post-2008  
proposals, which Don summarized, to use the wide-field capabilities  
of the telescope to do a host of interesting and largely unique  
science projects, some with the existing instrumentation and others  
requiring the advent of new instruments.  In figuring out which of  
these programs to push forward, there are difficulties relating to  
the continuing lateness of the NSF Senior Review, and in blending  
several of these proposals into an integrated program like SDSS-II;  
it will take months and lots of back and forth dialog within ARC to  
resolve this.  Furthermore, the committee will recommend  
consideration of restructuring ARC in a manner that can allow  
continued operation of both telescopes in the absence of agency  
funding support.

ACTION:  BruceG to forward Futures documents to Users Committee  
members, who then help the institutional Futures Committee member  
share them with their faculties and gather feedback.


Previous Meetings Action Items report:

[open from previous months]:

ACTION:  The Users Committee members will need to help disseminate  
the [Futures Committee] draft report to their users.  STATUS:  Draft  
coming soon.

ACTION:  BruceG will ask Russell Owen what the pros and cons are of  
keeping TUI compatible with older versions of operating systems and  
libraries.  STATUS:  Discussed with RO, no final decision yet.

ACTION:  Users Committee members should poll their users to ask if  
there are compelling reasons to keep TUI operable without using the  
latest version of operating systems.  STATUS:  Open, only little  
feedback so far.

ACTION:  [re Triplespec white paper] The committee members are to  
forward any feedback to Suzanne within a week, from which she will  
report our assessment to the ARC Board of Governors.  STATUS:   

[new actions from last month]:

ACTION:  BruceG to discuss issues of computer and network security  
with Fritz Stauffer.  STATUS:  Working group (staff and invited  
users) being formed to frame requirements.

ACTION:  UC members should poll their constituents about ToO  
observations on the telescope.  Do they envision doing this type of  
science? Would expanding ToO opportunities be useful to them?  How do  
they feel about being asked to voluntarily give up time, and to  
having their time pre-empted (perhaps with later payback)?  STATUS:   
Discussed in 5/1 Users Committee meeting.

ACTION:  BruceG will ensure that the orientation checklist is up to  
date and available on-line, so that prospective new users can review  
it prior to their orientation site visit.  STATUS:  Open, plan to  
complete in early May.

ACTION:  Jon Holtzman to talk to Fritz Stauffer and BruceG about  
installing a RAID backup at NMSU.  STATUS:  Discussed, system  
components ordered.


Next Users Committee phonecon will be on Monday, 12 June, at 8:30 AM  
Pacific Time.  Agenda and other materials will be sent to the  
committee members during the preceding week.

APO APO APO APO APO  Apache Point Observatory 3.5m  APO APO APO
APO  This is message 963 in the apo35-general archive. You can find
APO  the archive on
APO  To join/leave the list, send mail to
APO  To post a message, mail it to