Subject: belated) APO 3.5m users committee minutes, June 2011

From: Suzanne Hawley

Submitted: Wed, 13 Jul 2011 15:11:22 -0700 (PDT)

Message number: 1233 (previous: 1232, next: 1234 up: Index)

NOTE: Information item on echelle received after the June meeting

The ThAr lamp was replaced on June 6, and the replacement lamp has a 
quartz window which makes many of the lines, especially in the blue, very 
faint and unusable for wavelength calibration. Echelle users who have data 
from before June 6 are warned that they will likely not be able to use 
their existing wavecal template.  Instead, many of the faint blue lines 
must be manually removed from the wavelength solution.  We will discuss 
further at the next users committee meeting on August 8.


 		APO 3.5-m Users Committee Phonecon, 6/06/11

Attending:  Suzanne Hawley, Al Harper, Bill Ketzeback, Bruce Gillespie, 
John Bally, Jon Holtzman, Michael Strauss, Russet McMillan, Scott Anderson

Absent:  Mark Klaene, Remy Indebetouw, Sean Moran


User feedback and comments from institutional representatives:

o Washington (Scott Anderson) - Scott had nothing new to report.

o Colorado (John Bally) - John had nothing new to report.

o Johns Hopkins (Sean Moran) - No report.

o New Mexico State (Jon Holtzman) - Jon had nothing new to report.

o Princeton (Michael Strauss) - Michael had nothing new to report.

o Virginia (Remy Indebetouw) - No report.

o Chicago (Al Harper) - Al had nothing new to report.


Discussion of telescope/instruments report:

Bill Ketzeback gave an overview of the past month's activities.  Although 
forest fires have been and are burning in the local area, there has been 
no significant impact to site operations.  We have had a small amount of 
rain in the past week, the first since January, and although the rain is 
appreciated we worry about so-called dry lightning.  Observing conditions 
have been generally good.  The telescope has behaved well; a small change 
in implementing pointing model corrections was effected that should 
improve telescope pointing and tracking slightly.  The replacement camera 
for the Shack-Hartmann wavefront sensor has just arrived, and will be 
installed in the coming weeks.  The driver card for the DIS grating turret 
motor failed, and has been fixed in spite of trouble using the 
documentation for it.  SPIcam is OK, although it is running a little 
warmer than we would like.  The problem with the Agile instrument rotator 
was fixed.  Some shims and adjustment to the NA2 clamps has fixed the 
TripleSpec mounting problem, but a generic redesign of the clamps in being 
considered.  The echelle shutter failed this past weekend [ed: since fixed 
by wiggling a cable, which will be replaced].  The NIC-FPS reset failures 
when upside down persists -- the operational workaround is being used, and 
the instrument will go back to CU to have its internal cables replaced 
next month.  The Goddard team is back at the site to continue the 
integral-field and detector upgrades to the GFP.

Mark Klaene's detailed report for the reporting period follows:


 	3.5-m Telescope, Instruments, and CIF Projects Highlights
    	                 5/6/11 through 6/1/11

0) Overview

The forest closed on May 12 due to critical fire danger.  Immediately 
following, a large fire, caused by a downed power line, started 20 miles 
northeast of us, ultimately burning 32,000 acres.  APO operations have not 
been affected by the closure.  Despite being through May, the winds have 
continued near the levels of April.  Short telescope closures due to dust 
and smoke have occurred a few times during this period.

1) Telescope

The telescope continues to operate routinely with minimal problems during 
this period.  Some minor changes to pointing models have been 

The Shack-Hartmann camera controller failed and a new camera and 
controller have been purchased.  We will be replacing the Apogee camera 
with a new SBIG camera.  Camera delivery is expected this month.

2) Instruments

DIS performed well this period until a failure of the turret motion.  The 
instrument was configured that the turret could be moved by hand which 
causes a loss of about 15 minutes if grating sets need to be changed 
during the night.  The cryotiger was adjusted but it seems to have had 
little effect.  The camera is still running 10-12 deg C warmer than 
previous when ambient temperatures are warmer.  We hope to wait until 
summer shutdown to investigate further.

SPICam operated with no new issues.

Agile rotator fault was corrected; a problem induced by the new locking 
pin was found to be the cause.

A TripleSpec problem has been diagnosed where the instrument comes off the 
kinematic mounts slightly when rotated upside down.  No effect on science 
has been reported and the instrument safety is not at risk.  A temporary 
solution to adjust the clamps and shim the pawls on the instrument was 
done and appears to have been successful.  New clamping/mounting systems 
are being investigated.

The Echelle worked with no problems this period.

The NIC-FPS problem of spontaneous reset of the Leach controller when 
rotated upside down still exists.  Users are advised to start their 
observations at specific recommended rotation angles, depending on sky 
position, to avoid tracking upside down. The instrument will be taken to 
CU on June 20 for a period of approximately 6 weeks.

GFP upgrade work has resumed on the mountain with an engineering run 
coming up next week.


Reporting JD in FITS headers:

Suzanne said that there is a request to report Julian date in the FITS 
image headers.  The issue is which time system to use as the standard. 
SDSS reports MJD in TA1, which is what we are suggesting for the 3.5-m 
instruments.  Michael felt that this was fine, if things are 
well-labelled.  Suzanne suggested that we can describe this on the web in 
the user documentation.  Bill said that the instrument computers can and 
do report in multiple time systems, especially the older computers.  So 
setting a MJD-in-TA1 standard would require changing some software for the 
older instruments.  It was generally felt that having a standard time 
system was probably a good idea, but that we should see if the users 
really want it to justify the extra work involved.

===> ACTION:  Users Committee members to ask their users if MJD in TA1 would 
be useful information to have written in the FITS headers.


Possible new instrument(s):

Suzanne mentioned a couple of items.  First, we discussed several months 
ago the possibility of getting a multi-band griz imager that Chris Stubbs 
is involved with at CfA, called PISCO.  Chris in interested in possibly 
deploying the camera at APO and will send us a proposal.  The terms of its 
use at the 3.5-m telescope would need to be negotiated.  The camera has a 
FOV of approx. 10 arcminutes.  There are questions about telescope 
baffling changes, and whether the filters are changeable.  We need more 
feedback on the desirability of PISCO from the user committee and general 
users.  Michael mentioned the Princeton would be very interested in the 
instrument.  Jon Holtzman was concerned that PISCO doesn't have all the 
capabilities that SPIcam has (i.e., narrow-band filters), so if PISCO 
replaced SPIcam, it is not clear that this is win-win.  There is concern 
that SPIcam will fail in the near future and not be easily repaired. 
There is also a floor-space issue on the NA2 side of the telescope -- we 
may need to retire an instrument in order to find room for a new one.  In 
any case, we need to hear back from the user community about the pros and 
cons of this possible new instrument.

Second, Jon Holtzman has been talking with Matthew Shetrone at UT about 
IFUs.  The HET is having several built, and it may be possible to get one 
additional copy made for use at APO.  It's not clear if this IFU would be 
better than the IFU upgrade underway for the GFP.  Michael said that there 
may be people at Princeton interested in an IFU on the 3.5-m.


Misc. topic - ReSTAR:

Jon mentioned that he got a note from NOAO that they are starting to write 
the joint ReSTAR proposal for NSF funding, and we need to decide on the 
terms of our participation.  Discussions are ongoing.


Summer telecon schedule:

Suzanne said that there will be no Users Committee telecon in July during 
the summer shutdown.  The next telecon will be 8 August.  The following 
telecon will be in late September or early October.



[open from previous meeting]:

===> ACTION:  User committee members to try to find users who would be 
interested in helping develop exposure time calculators.

 	STATUS:  Scott said that Anjum Mukadam is willing to develop exposure 
calculators for Agile, and likewise Sarah Schmidt for TripleSpec.  Suzanne 
said that George Wallerstein is willing to help with the echelle.  Jon noted 
that this really needs to be done in a single framework, and Bruce suggested 
that we import an existing exposure calculator architecture from NOAO or 
STScI, for example.  Suzanne decided to leave the action item open, giving 
the Users Committee members more time to ask for help and to look into the 
possibility of importing a framework from elsewhere.

[new actions from this meeting]:

===> ACTION:  User Committee members to ask their users if MJD in TA1 would be 
useful information to have written in the FITS headers.


Next meeting:  The next Users Committee phonecon will be on Monday 8 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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