[mmaimcal] BIWEEKLY CALENDAR OF THE ALMA PROJECT at NRAO

Mon Oct 11 16:32:30 EDT 2004

Folks

I'll be representing ALMA at the meeting at U. Md. tomorrow, so no imcal meeting again
this week.  Remember the Calibration Group telecon on Thursday however.

Al

                        BIWEEKLY CALENDAR OF THE ALMA PROJECT at NRAO
                           October 11, 2004 -- October 27, 2004

******************************** THIS FORTNIGHT*********************************

The ALMA Management Advisory Committee meets 11 - 12 October in Florence,
Italy with the ALMA Management IPT and the JAO.
---------------------------------------------------------------------------
The ALMA Science Software Requirements Committee meets 11 - 12 October in 
Garching, Germany.
---------------------------------------------------------------------------
Simon Radford announced that he will depart NRAO 2004 November 1 to assume a post
at Caltech as Asst. Project Manager for the Caltech/Cornell 25m telescope to be 
constructed at Chajnantor.  Simon pioneered the characterization of the Chajnantor 
site, now home to several observatories--CBI, ASTE, APEX and a new survey telescope
from Nagoya Observatory.  As Site IPT lead for NA he has managed the planning for
the construction of the AOS on the site.  
---------------------------------------------------------------------------
Domenick Tenerelli has resigned from AMAC and will not be at the Florence meeting
of the AMAC being held 11-12 October.  He has served on the AMAC and its
predecessor, the MOC, since their inception.Lockheed Martin Corporation
---------------------------------------------------------------------------
Janet Bauer has resigned from NRAO on 1 October.   
---------------------------------------------------------------------------.
John Webber has agreed to become the new ALMA Front End IPT Leader, replacing 
Charles Cunningham and reporting to the NA ALMA Project Manager.  Charles will 
remain in the FE IPT as senior technical expert contributing to high level 
design work.  John will also retain his position as ALMA Correlator IPT Leader. 
---------------------------------------------------------------------------.

Past issues of this Calendar may be viewed at 
http://www.cv.nrao.edu/~awootten/mmaimcal/ALMACalendars.html
*******************************************************************************

General Happenings

No new reports this week.

DAILY CALENDAR (Times EDT )
Mon 11 October
All day events: NRAO Holiday
               AMAC Meeting, Florence, Italy
               SSR FAce-to-face Meeting, Garching, Germany
Tue  12
All day events: NRAO Holiday
               AMAC Meeting, Florence, Italy
               SSR FAce-to-face Meeting, Garching, Germany
 Wed  13
 Thu  14
11:00 AM 
 Fri  15 October
 10:30 AM-11:30 AM: CCB Meeting
 Sat 16 
 Sun 17 
 Mon 18
9:30 AM-10:30 AM: NA Project Office Staff Meeting
 Tue  19
 10:30 AM-11:00 AM: Science IPT Telecon
 Wed  20
 Thu  21
8:30 AM-10:00 AM: JAO Teleconference
 Fri  22  
 Sat  23  
 Sun  24

****************************** UPCOMING EVENTS ******************************
ALMA Calendar  

    * 11-12 Oct -- AMAC Meeting, Florence, Italy
    * 11-12 Oct -- Science Software Requirements group meeting, Garching
    * 11-13 Oct -- New Windows on Star Formation in the Cosmos
                    University of Maryland, College Park, Maryland
    * 18-19 Oct --  PDR for the Tunable Filter Bank card; Bordeaux
    * 19 Oct -- ASAC Telecon
    * 27-29 Oct -- Dusty and Molecular Universe Paris
    * 29 Oct -- ANASAC Telecon
    * 1 Nov -- ALMA JAO and Executives Face-to-face Meeting, Santiago
    * 2-3 Nov -- ALMA Board Face-to-face Meeting, OSF, near San Pedro de Atacama
    * 2 December -- ALMA Board Telecon
    * 5-7 Jan 2005 -- UNSC URSI Boulder meeting Commission J
    * 6 Jan 2005 -- ANASAC Telecon
    * 11 Jan 2005 - ALMA Town Meeting, AAS San Diego
    * 27 Jan 2005 -- ALMA Board Telecon

******************************* TECHNICAL NEWS *******************************
ALMA Memo # 505 Bandpass Calibration for ALMA A. Bacmann (ESO), S. Guilloteau (IRAM/ESO)

This memo contains a detailed evaluation of the expected performance of 
the bandpass calibration for ALMA. We evaluate the limitations on the bandpass 
accuracy due to the imperfect knowledge of the atmospheric transmission. We 
show that the best bandpass accuracy is obtained when the amplitude calibration 
is applied in a single-load scheme. The proposed scheme is a variant of the 
so-called bandpass normalization technique. It uses normalization by the difference 
between the sky emission and the load emission, rather than normalization by the 
auto-correlation spectrum in the usual case. Bandpass calibration should be 
performed at the observing frequency. It will be limited by the knowledge of 
the sideband opacity difference. This knowledge can be based on a model, but 
a direct measurement is also possible, although time consuming.

The bandpass calibration must be performed on strong point-like sources, of 
known spectral index. The knowledge of the spectral indexes will be a limiting 
factor in the wide band modes. Building up a database of suitable sources will 
be necessary, since the knowledge of these spectral indexes could be improved 
by bootstrapping techniques among several sources. Since astronomical sources 
have to be used, the required integration time varies substantially as a 
function of frequency. High accuracies can be reached in a minute of time 
at mm wavelengths, but integration time as large as an hour can be needed 
at sub-mm wavelengths. Occasional direct measurements of the sideband opacity 
difference could also be used to improve the accuracy of the atmospheric 
modelling.

View a pdf version of ALMA Memo #505 at 
http://www.alma.nrao.edu/memos/html-memos/alma505/memo505.pdf
---------------------------------------------------------------------------.
ALMA Memo # 483 The ALMA 1st Local Oscillator Reference  Bill Shillue, 
Sarmad AlBanna, and Larry D'Addario  National Radio Astronomy Observatory

The ALMA 1st LO Reference system consists of a laser synthesizer, active 
line length correction, photonic distribution, and a photonic receiver. 
The phase stability and phase drift specifications are very ambitious, 
and the effort to meet them has led to small evolutions and improvements 
in the design. This memo gives a general description of the system, and 
documents its current measured performance levels, as measured in the 
laboratory.

View a pdf version of ALMA Memo #483  at 
http://www.alma.nrao.edu/memos/html-memos/alma483/memo483.pdf

*******************************ALSO OF INTEREST*******************************

*******************************************************************************     
Please send information for upcoming calendars by Friday evening of the
preceding biweekly period to Jennifer Neighbours or Al Wootten via e-mail 
(jneighbo at nrao.edu or awootten at nrao.edu).

The calendar will be issued between late Friday and sometime on Monday by e-mail
to all NRAO scientific staff members and anyone else interested. A specific
mailing list, alma-info, has been created for anyone wishing to receive it.  Past issues
are now available at http://www.cv.nrao.edu/~awootten/mmaimcal/ALMACalendars.html