MMA Imaging and Calibration Group
Minutes for meeting Tuesday, 8 Oct 2002 at 12:00pm EDT.
Date: 8 Oct 2002
Time: 4:00 pm EDT
(2:00 pm Socorro, 1:00 pm Tucson)
Phone: (434)296-7082 (CV SoundStation Premier Conference phone 3rd floor).
Past minutes, etc on MMA
Imaging and Calibration Division Page
Agenda
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Science IPT News - Wootten
News from my point of view.
The VertexRSI antennais up!
John Webber asks: 'When the prototype 2-antenna, full-IF ALMA correlator is delivered
to the VLA site, what modes of operation are needed?
'This question has arisen in the context of planning the firmware
and software checkout; for example, there would seem to be no need
to support sub-arrays--but is there a need to support separate
autocorrelator modes for each of 2 antennas? Do we need every
possible bandwidth?'
The purpose of the prototype interferometer is to test ALMA
components, so the correlator should provides modes useful for those tests.
Although I have not seen a detailed plan, my understanding is that a pacing
item for the interferometer is the availability of ALMA frontends. There
is a problem that the first prototype Band 6 receivers are not due at the
prototype interferometer until mid-2005 (I do not know the schedule for
others). If the prototype interferometer is to be used with
the evaluation receivers from 1Q2004-3Q2005 it may be necessary to design
some equipment to interface them. I don't think this will impact the
autocorrelator modes, however. Some interferometric holography
will be done, using SiO masers, so at least one narrow band mode will be
needed to support this. Wideband modes will be useful for evaluating
standing wave patterns, for instance with the calibration devices.
The widest wideband modes will be useful for the prototype
receivers, so they should be available. Modes matched to the IF of the
evaluation receivers may be useful, depending on the poorly defined
prototype interferometer plan.
I'll go through this more throroughly this week. However, right now
I can think of no essential test which requires separate autocorrelator
modes operating independently for the two antennas.
Project News -
JAO-only Configuration Final Review -- Grenoble 30 Sept - 8 Oct 2002.
NRAO Director's ALMA Frontend Review 2002 October 3-4 NRAO Charlottesville.
Science IPT Lead Telecon 1400 UT 8 October 2002
Mitsubishi at ATF 17 October
ALMA/JP meeting Tucson 20 October
ALMA Science IPT Telecon 1500 UT October 22
ALMA Site Infrastructure Requirements Review 2002 October 22-24 NRAO Tucson
ALMA Antenna Transporter Requirements Review 2002 October 22-24 NRAO Tucson
ACC or ALMA Board meeting 2002 29-30 October Santiago.
ESO Workshop: Science Operations with ALMA, ESO, Garching 8 Nov 2002
ALMA Frontend/LO Reviews 18-22 November Charlottesville.
Carla Beaudet and Galen Watts of NRAO/GB conduct RFI tests at Chajnantor 3 - 20 December 2002
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Calibration - All
Milestones and planning revised. Telecon next week.
John Payne notes the interesting report in Electronics Letters
V. 38, No. 15, p 798 on a device similar to plans for the photonic calibration
device.
Note Shillue's email of 14 August, where he pointed out that
1. the costs of this system are unknown ranging from an expensive phase locked
system downward; that
2. swept in frequency, power will vary by >> 1%, ''much
lower but still significant for a broadband lens-antenna. The ouput power will
also change with time at a fixed frequency due to polarization effects
in the fiber. The time scale of the changes depends on environmental
factors not well understood without a field test. Careful calibration
and polarization control could be used to mitigate these variations.
3. The types of tests that are do-able at the ATF are limited. The only
calibrator is the one on the holography tower so that is a bit different
from a subreflector-mounted source. The frequency is not sweepable, but
can be stepped from about 70-110 GHz.
4. Practically speaking, there is no manpower set aside for photonic
phase cal, no specifications, no system design, no schedule, and the
budget is fictitious for lack of a better word.
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AIPS++ -
A report for the ASAC was conveyed to them. Comments? Flagging looks like
it wasn't done. Reports of difficulties reproducing these results by
one member of the science IPT. Has anyone else tried?
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Configuration - Holdaway
Please see Holdaway's Conway ASAC presentation.
The JAO will approve the configuration plan 30 Sept - 1 Oct in Grenoble.
John has submitted a plan but wishes to tidy it up some before releasing
it to ImCal.
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Meetings Past and Future - Wootten
Presentations for ASAC Face-to-face.
The ASAC will hold a telecon on 9 October. Its report is to be
finished by 3 October.
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Other
A
monthly report for September has been submitted to the Science IPT. A bimonthly report
is still due to NSF. Please send your report for August
and September activities, as this is due shortly.
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SMA News...
SEP 30, 2002 Congressional milestone: routine science imaging with five
antennas at 345 GHz; phase closure at 650 GHz.
available in draft form:
xxx Noise Characterization and Allan
Variances of Water Vapor Monitors Wiedner
********************************* DEPARTURES *********************************
OCT 15(tbc) Martina Wiedner
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Upcoming Meetings - Wootten
JAN 5/9, 2003 201st Meeting of the American Astronomical Society
JUL 13-26, 2003 Twenty-Fifth General Assembly of the IAU
JUL 22/25, 2003 IAU Symposium (221): Star Formation at High Angular Resolution, Sydney, Australia. Tyler
Bourke is a co-chair of the scientific
organizing committee. Good opportunity to show ALMA capabilities.
SEP 22-26, 2003 4th Cologne-Bonn-Zermatt-Symposium on The Dense Interstellar Medium in Galaxies
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Travel
Oh, always
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