[mmaimcal] BIWEEKLY CALENDAR OF THE ALMA PROJECT at NRAO - 05Mar14
Al Wootten
awootten at nrao.edu
Mon Mar 14 16:40:09 EST 2005
Folks,
Please note back to me additions, deletions, and incompetencies.
Thanks,
Al
BIWEEKLY CALENDAR OF THE ALMA PROJECT at NRAO
March 14, 2005 -- March 28 2005
******************************** THIS FORTNIGHT*********************************
Chris Carilli, has just been given and accepted the 2005 Max Planck Research
Award by the Alexander von Humboldt Foundation and the Max Planck Society
in Germany. The award carries with it a research stipend of 750,000 Euros
over five years. Congratulations Chris!
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Crystal Brogan has accepted the NRAO Director's offer for
an NRAO tenure-track Assistant Astronomer position, to be based in
Charlottesville beginning March 14, 2006. Crystal's primary
responsibility next spring will be to assist in the establishment and
operation of the North American ALMA Science Center (NAASC) and the
commissioning of ALMA into an operational facility under the supervision
of the Head of NAASC, currently Paul Vanden Bout. Welcome, Crystal!
----------------------------------------------------------------------
Jody Bolyard begins as JAO Safety Consultant in July. Nice new hat, Jody.
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George Reiland left NRAO on 4 March after eleven years of service in Tucson.
He has taken a position at Steward Observatory. Thanks and good luck George!
----------------------------------------------------------------------
George H. Clark will join the NRAO staff
as the Associate Director for Administration (ADA) on April 12, 2005.
As ADA he will have overall responsibility for all administrative and
business functions at the Observatory. Welcome, George.
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Past issues of this Calendar may be viewed at
http://www.cv.nrao.edu/~awootten/mmaimcal/ALMACalendars.html
*******************************************************************************
General Happenings
Santiago: Rebaselining activities continue.
OSF: Construction of the 30 bed extension to the ALMA camp should begin shortly,
to be completed by the end of May. Release of bidding documents for Contractor's
Camp extension in process, work to be completed end of August. 26 persons are
working on the site.
Tucson: Preliminary tests of revised Line Length Corrector are underway. Adrian
Russell will be visiting the birthplace of millimeter astronomy the week of 14
March.
ATF: Fast switching tests continue; cumulative total now well into the tens
of thousands per antenna involving numerous NA personnel.
Initial radiometry at 1.3mm with AEC antenna performed.
AOC: Preparations for Central Variable Reference (CVR) review 29 March.
Team from AOC visiting ACC (contractor) to witness acceptance testing of first
prototype IF Downconverter.
NTC: Assembly of Cartridge No. 2 for Band 6 (1.3mm) is complete. Progress has
been made on understanding optics anomalies.
The first Tunable Filter Bank (TFB) card spectral test made with the Test
Fixture (test No 7, in which one sub-channel is autocorrelated and the
spectrum displayed) works well; a line can be moved around as predicted through
the selected sub-channel.
*******************************************************************************
DAILY CALENDAR (Times EST )
Mon 14
9:30 AM-10:30 AM: NA Project Office Staff Meeting
10:30 AM-11:30 AM: JAO IPT Telecon
11:30 AM-12:30 PM: NA DH telecon
Tue 15
9:30 AM-10:30 AM: ALMA Science IPT Telecon
10:30 AM-11:30 AM: ASAC Telecon
Wed 16
Thu 17 St. Patrick's Day!
All Day: G. Helou visiting NAASC
9:30 AM-11:00 AM: Management IPT Teleconference
4:00 PM: Spitzer Space Telescope: Extragalactic Results
Fri 18 NRAO Spring Holiday
Sat 19
Sun 20 Spring Begins 12:33 UT
Mon 21
9:30 AM-10:30 AM: NA Project Office Staff Meeting
15:30 - 17:30 IEEE ICASSP: Towards a New Generation of Radio Astronomical
Instruments: Signal processing for large distributed arrays
Tue 22
No ImCal telecon today
Wed 23 AAS Minneapolis Abstract Deadline
Thu 24
Fri 25 Good Friday
Sat 26
Sun 27 Easter Sunday
****************************** UPCOMING EVENTS ******************************
ALMA Calendar--see also https://wiki.nrao.edu/bin/view/ALMA/NAASC
* 18-23 Mar 2005 -- Philadelphia ICASSP/IEEE meeting, Philadelphia
* 22-24 March 2005 -- JAO/IPT Meeting, Garching
* 29 March 2005 -- Central Variable Reference review, Charlottesville
* 4 April -- Executive meeting, Pasadena
* 5-6 April 2005 -- AMAC Face-to-face meeting, Pasadena, CA.
* 7-8 April 2005 -- ALMA Board Face-to-face meeting, Pasadena, CA.
* 9 April 2005 -- Bilateral project meeting
* 4-5 May 2005 -- WVR PDR, OSO, Gothenburg, Sweden
******************************* TECHNICAL NEWS *******************************
ALMA Memo # 515 Calculation of Integration Times for WVR
by Alison Stirling, Mark Holdaway, Richard Hills, John Richer
2005-03-02
Abstract:In this memo we address the issue of how to apply water vapour
radiometer estimates of atmospheric phase to visibility data. We consider the
impact of smoothing the radiometer data over a period of time to reduce the
noise in the w.v.r. estimate, and applying a multiplicative factor to decrease
the impact of the w.v.r. estimate when the phase fluctuation amplitude is small
compared with the radiometer noise.
We find that when fast-switching is taken into account, for fully three-dimensional
turbulence, and r.m.s. path length fluctuations of order 75 micros', the optimal
smoothing timescale is 11 seconds. This timescale decreases to around 3 seconds
as the thickness of the turbulence layer becomes small compared with the baseline
length. These values are found to decrease as the r.m.s. fluctuations increase.
A multiplicative factor is required to modify the w.v.r. correction term for
fluctuations less than ~ 50 microns', where the noise in the radiometer becomes
comparable to fluctuations at the site.
View a pdf version of ALMA Memo #515:
http://www.alma.nrao.edu/memos/html-memos/alma515/memo515.pdf
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Long baseline (Y+) 64 antenna array configuration: Specification and requirements;
(ALMA-90.02.00.00-002-A-SPE) by M. Holdaway was approved.
Summary:
Beyond the inner 78 antenna stations that are arranged in a compact configuration,
Conway’s stations are governed by a three-armed logarithmic spiral. The
resolution is increased in increments of about 15% as four antennas are moved
from one configuration to the next. The Chajnantor site permits this spiral
configuration out to baselines of 4500 m. The outer 44 stations continue this
general philosophy of incremental reconfiguration, but the three arms cannot
continue in a spiral due to the mountains, so the three arms straighten out in a
rough “Y” shape. A Y shaped array with straight arms and regular antenna
placement produces poor snapshot (u,v) coverage and high side lobes in the point
spread function (PSF), so our “Y” arms are actually 5 or 6 km wide at
their ends. To maximize the resolution, antennas are placed as far apart as
the land concession permits.
View a pdf version of ALMA-90.02.00.00-002-A-SPE:
http://www.cv.nrao.edu/~awootten/mmaimcal/2003-06-30ALMA-90.02.00.00-002-A-SPE.pdf
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Status of the Atacama Large Millimeter Array, contribution to the conference:
The Cool Universe: Observing Cosmic Beginnings held 2004 October 4-8 at
Universidad Tecnica Federico Santa Maria, Valparaiso, Chile
by Wilson, Beasley and Wootten
Abstract: The Atacama Large Millimeter Array is a large international
telescope project which will be built over the next decade in northern
Chile on a site at 5 km elevation. The site provides excellent atmospheric
transmission in the millimeter and submillimeter wavelength ranges. The project
consists of two parts: (1) the "12m Array", composed of sixty-four 12-meter
antennas that can be placed on 216 different stations for baselines up to 18 km
(see Table 1) and (2) the "Atacama Compact Array", or ACA, that consists
of twelve 7 meter telescopes placed in compact configurations and four
12 meter telescopes for measuring total source power. In addition to
high sensitivity, frequency coverage and dynamic range, ALMA
will record both interferometric
and the complete source flux density. At the shortest planned
wavelength, lambda=0.3mm, and longest baseline, the angular
resolution will be 0.005". The receivers use superconducting (SIS)
mixers, to provide the lowest possible receiver noise contribution.
At first light, the ALMA project's 6 highest priority receiver bands
will be installed (see Table 2), each observing both polarizations
with a bandwidth of 8 GHz. In the following, we present the status of the
ALMA project as of late 2004.
View a pdf version of ALMA-90.02.00.00-002-A-SPE:
http://www.cv.nrao.edu/~awootten/mmaimcal/CoolUniverseOct04.pdf
*******************************ALSO OF INTEREST*******************************
******************************************************************************
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