[mmaimcal] FYI: April 2010 MONTHLY CALENDAR OF THE ALMA PROJECT at NRAO

Fri Apr 23 17:22:22 EDT 2010

Folks

Corrections, contributions or clarifications??

Clear skies,
Al

            MONTHLY CALENDAR OF THE ALMA PROJECT at NRAO
                          April 2010

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ALMA’s Compact Array

On 1 April antenna DV02 was moved to an antenna foundation eventually
slated to hold a 7m diameter antenna of the Atacama Compact Array (ACA).
  In this current array there are two 30m baselines and one
18m baseline.  With such short baselines atmospheric variations
affect signals less than on the baselines of over 100m which had
previously been used.  Cooler autumn temperatures also ensured a
somewhat lower turbulent component in the atmosphere.  A key goal
of  April commissioning was therefore to verify antenna performance
at high elevations (measurements at the Operations Support Facility
are limited to tower beacons at low elevation) and in cooler windier
weather.  The method used to validate antenna performance is
astroholography—that is, holography using astronomical sources.
Planets are bright but scarce and many are resolved even on short
  baselines at 3mm and shorter wavelengths.  Quasars are more
abundant but only moderately bright.  These factors limit
sensitivity to surface errors on meter scales.  Initial tests
show that the telescopes are performing as predicted by models
based on lower elevation measurements at the warmer OSF; these
models include gravitational sag of the telescope structure.
Smaller scale surface errors may be measured through observations
of distant sidelobes of bright sources; Sun and Moon observations
were made to constrain this.  With atmospheric distortion
minimized, sensitive tracking tests were carried out.  Other
tests focused on phase stability and other characterizations
of the ALMA system.  In the compact array, the telescopes are
  powered by the first phase of the single AOS power system rather
than by multiple generators.

At the 2900m altitude of the OSF new antennas and electronics
were accepted, integrated and tested.  One or more of the four
antennas there will be transported to the AOS for incorporation
into the array during May, even as newly assembled antennas
will be accepted by the project into the OSF compound from the
manufacturers for their integration and tests.  At present the
four antennas at the OSF are deployed with two in interferometric
testing and the other two in total power tests, eventually to
be incorporated in the interferometer as its elements migrate
to the AOS.

At the contractor’s camps, assembly continues.  Notably, the
‘dish’ structures of two AEM antennas, fully tiled with their
reflector panels, were mounted onto their pedestal and cabin
structures during the month.  Further assembly now proceeds.
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Past issues of this Calendar may be viewed at
http://www.cv.nrao.edu/~awootten/mmaimcal/ALMACalendars.html
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General Happenings
Photos of activity may be found at NRAO eNews:
http://www.nrao.edu/news/newsletters/

Sky:  Venus passes between the Pleiades and the Hyades, nearby
star clusters.  Mars is getting further and fainter.
Saturn is high overhead.  As its rings are nearly
edge-on, its satellites are lined up with the rings and well
placed for identification.  Titan is the brightest, revealed
by moderate-power binoculars.  Full Moon on 27 April.  The
Sun is quiet.

AOS: A fourth antenna, Vertex antenna DV03, is scheduled to be moved to 
the  AOS from the OSF, where it is undergoing final verification testing.

OSF: Vertex antenna DV07 is scheduled for acceptance during the end
of April followed by a move to the OSF TF.  DV04 panel setting was
completed, to a surface of 8 microns at the tower elevation.

NAASC: An ObOps face-to-face meeting was held at the East Asian ARC node 
in Mitaka, Tokyo.

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DAILY CALENDAR (Times EDT/EST ) see
https://wikio.nrao.edu/bin/view/ALMA/AlmaCalendar
      May 17-19    Cometary Radio Astronomy            Green Bank, WV
      May 24       Preparing for ALMA Session               Miami AAS
      Jun 8 - 15   12th Synthesis Imaging Workshop        Socorro, NM
******************************* TECHNICAL NEWS *************************
The ALMA Memo Series has a new URL:
http://science.nrao.edu/alma/documentation.shtml
The old URL should be redirected to the new location.
*****************************ALSO OF INTEREST***************************
NRAO Proposal Deadline   Jun 1, 2010 | 5:00 PM
No further information available at this time.
------------------------------------------------------------------------
CSO CALL FOR PROPOSALS     Due: 31 May 2010
The Caltech Submillimeter Observatory (CSO) encourages observing
participation by astronomers from both U.S. and non-U.S. institutions.
For instructions on applying and for information about available
instruments, including bolometer cameras, see
http://www.submm.caltech.edu/cso/cso-call.html. Applications for
observing time between 1 September 2010 through 31 January 2011 are
due by 31 May 2010. Applications will be reviewed by an outside peer
group.
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SOFIA BASIC SCIENCE
The Call for Proposals for Basic Science observations with the 
Stratospheric  Observatory For Infrared Astronomy (SOFIA) is now open. 
The deadline for responding to the call is Friday, July 30, 2010.
The Basic Science program will consist of about 75 hours of on-sky
exposure with either the FORCAST mid-infrared camera or the GREAT
sub-millimeter heterodyne spectrometer. The observing time is
expected to take place during a 2-3 month interval within the
time frame of March 1 through August 31, 2011. Documents needed to 
consider observational possibilities and constraints, and to prepare and 
submit observing proposals, can be found at:
http://www.sofia.usra.edu/Science/proposals/basic_science
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EVLA Commissioning Postdoc Position
All applications received by April 30, 2010, will be given full
consideration, but applications will continue to be accepted until the
position is filled.  Applications may be submitted online at
https://careers.nrao.edu.
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Past issues are available at
http://www.cv.nrao.edu/~awootten/mmaimcal/ALMACalendars.html