Subject: APO 3.5m users committee minutes, July 2009

From: Suzanne Hawley

Submitted: Wed, 15 Jul 2009 12:44:02 -0700 (PDT)

Message number: 1139 (previous: 1138, next: 1140 up: Index)

           APO 3.5-m Users Committee Phonecon, 7/13/09

Attending:  Suzanne Hawley, Ed Turner (for Michael Strauss), Jon 
Fulbright, Mark Klaene, Russet McMillan, John Bally, Bruce Gillespie

Absent:  Scott Anderson, Michael Strauss, Al Harper, Jon Holtzman, 
Remy Indebetouw


User feedback, comments from institutional representatives:

    Princeton (Ed Turner) - Ed had not heard of any user comments.

    Colorado (John Bally) - No general user comments, but John Stocke 
asked if a tip-tilt capability was being considered as part of the 
visible-light imager upgrade.  Suzanne said that it was not part of 
the landscape for the imager upgrade at this point; tip-tilt options 
for the  telescope and instrument had been considered extensively in 
recent  years, and the cost-benefit arguments were not compelling.  We 
are looking at the QUOTA camera from WIYN which uses orthogonal transfer
arrays and provides similar tip-tilt correction.  Bruce Woodgate is 
studying tip-tilt as a possible option on upgrades to the Goddard 
Fabry-Perot, and John said he would contact Bruce to see where 
he was.

    Johns Hopkins (Jon Fulbright) - Jon had not heard any comments from 
JHU users.

    Washington (Suzanne Hawley) - Things are basically fine.  UW users 
are looking into the Agile dome-flats issue.

    Chicago (Al Harper) - No report.

    New Mexico State (Jon Holtzman) - No report.

    Virginia (Remy Indebetouw) - No report.


Discussion of telescope/instruments report:

Regarding the more detailed report below, Mark said that weather was a 
major factor in observing success recently; we had unusually wet 
weather in late June, but the conditions have surprisingly dried out 
and observing has resumed.  Another activity worth mentioning is the 
influx of SDSS-III BOSS people, who are on site making preparations 
for the hardware and software upgrades for BOSS during the summer.

For the telescope performance, things have been generally pretty 
good.  During the June mini-shutdown, which went well, the  new 
altitude drive controller was installed and tested.  Tuning is still 
underway but the performance so far is very good, for which Fritz 
Stauffer deserves considerable credit.  Agile was moved to the 
TR2 port with its own dedicated rotator and 3-inch filter wheel. 
There is still some cleanup to do, but Agile is operational at its new 
permanent station.

For instruments, SPIcam, the echelle, and NIC-FPS are all functioning 
well.  There have been minor problems with the DIS vacuum system; new 
ion pumps have been ordered, and a long-term solution to the DIS 
vacuum maladies are under research.  The formal acceptance and 
handover of TripleSpec is moving forward, albeit slowly.  Extensive 
work has been done to study stray light issues in Agile (see later 
topic, this meeting), and we are modifying its filter mount to accept 
2-inch filters.  APOLLO observing has been generally fine.

The CIF projects arena is focussed on completion and installation of 
the direct drives for altitude and azimuth.  The drive assemblies are 
in the final phases of machining, and are expected at APO next week, 
which is close to the original schedule.  The big summer shutdown for 
their  installation is slated to begin 10 August.


3.5-m Telescope, Instruments, and CIF Projects Highlights, 6/04/09 
through 7/7/09

                           Mark Klaene

0) Overview

The monsoon rains arrived a little early this year, around June 15th-- 
we have already received four inches of rain for the season. 
Naturally, we have experienced more lost observing time because of the 
increased cloud cover, precipitation, and high humidity.  The SDSS 
BOSS group has also arrived en masse to start spectrograph and 
software integration; this will continue to tax our on-site housing 
resources throughout the summer.  The primary and tertiary mirrors 
were washed during the short shutdown this week.

1) Telescope

Telescope operations have been generally smooth, with some significant 
progress accomplished during the June engineering time. This includes 
the installation of the new altitude axis controller, and the move of 
Agile to its permanent mount on the TR2 port.  The transition to the 
new axis controller has gone better than we could have hoped for. 
Fritz Stauffer's hard work on this, and the prior integration of the 
NA2 and TR2 axes, paid off.  This will yield a major improvement in 
long-term maintainability of the telescope and eliminates a concern we 
have had for years with respect to failure of the old obsolete drive 
controllers.  In addition, the new controllers are paving the way for 
the direct-drive motors with their promise of improved pointing and 
tracking performance.

2) Instruments

SPIcam, Echelle and NIC-FPS have been operational with no problems. 
The high-frequency pattern noise on SPIcam reported last month seems 
to have subsided.

The DIS ion vacuum pumps have given us some trouble during this 
period, but we have been able to keep the instrument operational.

For TripleSpec, we are starting to make progress again on the 
instrument acceptance documentation.  Currently the digital slit mask 
is slightly off and we are waiting for available time to generate a 
new one.

Agile is operational on TR2.  The current status of the dome flats are 
under discussion and the instrument baffling is less than ideal--sky 
flats are an acceptable alternative.  There are a number of small 
clean-up items remaining, most of which have to do with operational 
issues like filter wheel handling, balance, homing, and zeroing--these 
are being addressed as time permits.  We also hope to have the 2-inch 
filter option back soon.

The APOLLO laser system is operational.

3) CIF projects

The direct-drive project is well on its way to having all of the 
telescope parts at the site by late July.  Machining schedules are 
very tight, but we are still on course for installation during the 
summer shutdown, scheduled for Aug 10-Sep 6. The new azimuth drive 
controller is being developed and initial testing has begun.


Update on recent July engineering work (Klaene):

Mark reported that the APO engineering staff successfully washed M1 
and M3, and the new hardware for the altitude and azimuth drive 
controllers was installed and tested.  All three telescope motions 
(alt, az, and rotators) are now running on new controllers, which is a 
major accomplishment and removes our dependency and risk related to 
the old controllers that were obsolete and unmaintainable.  Also, the 
M3 rotation logic has been modified so that the tertiary mirror moves 
more quickly between the primary science ports.  Some improvements to 
the tertiary mirror tip-tilt adjustments are being explored.


Agile dome flats at the TR2 port (Hawley):

At its new TR2 port, Agile dome flats show significant scattered 
light.  Sky flats appear to be OK, but on-sky tests near the moon
have not yet been carried out.  Recent tests have suggested several 
ways to improve the dome flats by identifying sources of scattered
light and changing the instrument baffling.  These are under 
investigation.  We are also considering building a library of 
good dome flats and sky flats for Agile users.  In the meantime, 
users should not use dome flats for science, and should instead obtain
sky flats.  We also will appreciate user feedback on their flats
and science data.


Improvements in FITS headers (Hawley):

There are 2 issues with FITS headers to discuss.  First, the headers 
have until recently contained incorrect gain and read noise
parameters for the DIS red chip, being the parameters from the old CCD. 
These were  replaced with the proper parameters for the new red CCD (which 
was installed in Dec 2006) in late June and are now correct in the DIS
FITS headers.  Second, LST entries in the headers were not correct
for the start of the exposure time.  This bug has apparently existed
for at least the past 10 years.  If data has LST written in scientific
notation, it should not be trusted.  The LST is now written in
sexagesimal notation (HHMMSS) and is accurate to within a second
of the exposure start time.  Note that the UT times written in the 
headers have always been correct, and if users need LSTs for older 
exposures, they can obtain them via manual computations based on the 
other data in the headers.  Committee members should make sure that 
their users know that these changes in the FITS headers have been made.
We appreciate the feedback from several users recently which led to us 
uncovering and fixing these issues.


Update on imaging camera and echelle upgrade studies (Hawley):

Cynthia Froning and Eric Burgh (both at CU) are heading up the studies 
for an optical imager and echelle spectrograph upgrade, respectively.

Cynthia provided the following update on the imager study:

Chris Burrows has been hired as a consultant and he has completed a 
preliminary optical design for a camera that covers a 10 arcmin FOV 
with no vignetting at 0.35 arcsec/pixel sampling.  We are currently 
using this baseline design to evaluate the trade space with regard 
to field of view, spatial sampling, and broadband and narrowband 
performance versus complexity and cost.  Our next steps will be
to extend the study to evaluating the feasibility of placing a camera at
the TR1 port rather than NA2 and examining the cost vs. performance
enhancements of expanding to a camera that provides simultaneous multicolor
imaging in multiple channels.  We plan to complete this work over the next
two months.

Suzanne mentioned that the QUOTA camera from WIYN is also under 
consideration during the imager study.

Eric Burgh provided this update on the echelle study:

Still hunting down current component level efficiencies for the detector,
grating, and optics.  Need these for adequate comparison to new components.
Received quote from Newport for an echelle grating with better
efficiency that could replace the current one.  Am still looking into 
quotes for AR coatings for the optics, as well as for the CCDs.

Don York is sending a large stack of echelle documentation to APO
which may be helpful.  Also, John Bally said that he recently discussed 
the echelle with Dale Sanford from Yerkes/UChicago who was involved in the 
building of the echelle.  He will put Dale and Eric in touch.


Shutdown status & plans (Klaene):

Mark reminded the committee that the main summer shutdown starts on 10 
August.  The main event is to replace the altitude and azimuth drive 
systems with direct-drive motors.  Users should be aware that with the 
usual summer weather vagaries, returning the telescope for science 
observing is tricky to schedule--we might be early, on schedule, or 
late.  Suzanne said that she will monitor the shutdown progress 
closely, and will alert the institutional schedulers if there is a 
need for programs to add if we finish the shutdown early, and will notify 
affected users if we are delayed in finishing the engineering work.


Date for next meeting (Hawley):

As we traditionally do, we will skip August.  The next Users Committee 
telecon will be on 14 September at the usual time (8:30am PDT).


Miscellaneous topics:

    o Suzanne mentioned that there are several postdocs at UW who need to 
have their training orientation trip to APO.  If other institutions 
have a similar situation, they should contact her to see if a pan- 
institutional postdoc-training program could be tried out.  Bruce said 
such a program should be advertised APO-wide, and he wondered if it 
might be possible to block some contiguous nights of telescope time 
for this purpose.  Suzanne said there are various scheduling 
possibilities if we know ahead of time (by the previous quarter) 
who/how many would be participating.

    o Ed Turner asked the committee if anyone had any comments about 
endorsing NMSU's request for ARC participation in the SONG proposal 
(SONG is the stellar equivalent of the GONG project).  There were no 
objections from the attendees.



[open from previous months]:


[new actions from this meeting]:



Next meeting: The next Users Committee phonecon will be on Monday, 14 
September (no meeting in August), at 8:30 AM Pacific Time.  The agenda 
and other materials will be sent to the committee members during the 
preceding week.

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