[mmaimcal] BIWEEKLY CALENDAR OF THE ALMA PROJECT at NRAO
Al Wootten
awootten at nrao.edu
Mon Jan 31 15:18:53 EST 2005
Folks,
Corrections, additions, evasions? Thanks, Al
BIWEEKLY CALENDAR OF THE ALMA PROJECT at NRAO
January 31, 2005 -- February 14, 2005
******************************** THIS FORTNIGHT*********************************
Budget worksheets for the ALMA rebaselining effort are due in the managers'
offices tonight. Statements of Work have already been delivered, along
with other items including risk assessments.
---------------------------------------------------------------------------
The ASAC will meet in a face-to-face meeting in Garching 24-25 February
to discuss Charges expected to be delivered to them by the Board late today.
There will be a face-to-face meeting of IPT leads and managers in
Garching 22-24 March to discuss the rebaselining options.
----------------------------------------------------------------------
A fiber management design review is scheduled to occur in Garching.
----------------------------------------------------------------------
Past issues of this Calendar may be viewed at
http://www.cv.nrao.edu/~awootten/mmaimcal/ALMACalendars.html
*******************************************************************************
General Happenings
Santiago: Intensive meetings between the JAO and Japanese project
management occurred in Santiago last week.
OSF: Completion of 22 bed facility at the Contractors Camp is the only
current construction activity at the site except for emergency road repair
as a result of torrential rainfall. 25 people are currently working at this
site.
ATF: Photogrammetry produced excellent results.
A further round of holography has been completed on the AEC antenna and
will proceed on the Vertex antenna. Out-of-focus holography has begun.
AOC: ATF support during antenna tests. Verification tests continue on prototype
modules for the prototype system integration. Antenna cable wrap designs
were studied.
NAASC: A preliminary study was assembled on ALMA solar observations.
NTC: Beam measurement analysis of 1.3mm cartridge continues. Delay model
firmware completed for prototype correlator to enable ATF interferometry.
Tucson: ATF support during antenna tests. Redesign of LO line length corrector
75% complete. Verification tests continue on prototype
modules for the prototype system integration. Tests are underway to study
phase drift with temperature.
HIA: Ongoing tests of B3 preproduction unit No. 1 show noise temperatures
38-45K with good image rejection.
DAILY CALENDAR (Times EST )
Mon 31 January
10:30 AM-11:30 AM: JAO IPT Telecon
Tue 01 February
10:30 AM-11:30 AM: ASAC Telecon
3:30 PM-5:00 PM: ALMA: Imaging Cosmic Dawn presentation at Johns Hopkins
Wed 02
Thu 03
9:30 AM-11:00 AM: Management IPT Teleconference
Fri 04
Sat 05
Sun 06
Mon 07
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 08
4:00 PM-5:00 PM: NAScienceIPT teleconference (open to all interested
parties) (434)296-7082
Agenda: http://www.cv.nrao.edu/~awootten/mmaimcal/
Wed 09
11:00 AM-12:00 PM: Software Science Req. Group Teleconference
Thu 10
9:30 AM-11:00 AM: Management IPT Teleconference
Fri 11
Sat 12 Happy Abraham Lincoln's Birthday!
Sun 13
Mon 14 Happy Valentine's Day!
****************************** UPCOMING EVENTS ******************************
ALMA Calendar
* 27 Jan 2005 -- ALMA Board Telecon
* early Feb 2005 -- Fiber Management CDR, Garching
* 24-25 Feb 2005 -- ASAC face-to-face meeting, Garching
* 24 Feb 2005 -- ALMA Board Telecon
* 20 Mar 2005 -- Philadelphia ICASSP/IEEE meeting, Philadelphia
* 22-24 March 2005 -- JAO/IPT Meeting, Garching
* 5-6 April 2005 -- ALMA Board Face-to-face meeting, Pasadena, CA.
******************************* TECHNICAL NEWS *******************************
(Memos# 507, 509, 512, 514 are available on almaedm and will be on www.alma.info
shortly; they will be featured in the next calendar.)
ALMA Memo # 510 The ALMA Digitizer (DG) Demultiplexer :
Design, Performances in DG Assembly and Production Acceptance Tests
by Cyril Recoquillon, Alain Baudry, Jean-Baptiste Begueret, Stephane Gauffre
Guy Montignac
Abstract: A high frequency, low power 1:16 deserializer has been
developed using the 0.25um BiCMOS SiGe technology from ST
Microelectronics to meet the ALMA project requirements. The input shift
register is clocked at 4 GHz and the output data are transferred at 250
MHz. Nominal operation has been observed up to 8 GHz. With 2.5 V supply,
the circuit dissipates around 650 mW an especially low value compared to
existing similar circuits. The chip is available in an industrial
package and exhibits low thermal resistance (about 25 uC/W) thus
implying long lifetime as required for the ALMA project. Functional
tests including those performed with a self-test block embedded in the
deserializer are briefly described. Our deserializer is integrated in a
prototype ALMA Digitizer assembly which includes a 3-bit (8-level), 4
GS/s sampler developed with the same SiGe process. Based on Digitizer
state counts measurements, Allan variance tests and long term operation
in the laboratory environment, we conclude that the prototype Digitizer
assembly is operational. The deserializer chip has reached the final
production stage after static and dynamic qualification tests have been
performed on a first restricted number of production chips.
View a pdf version of ALMA Memo #510.
http://www.alma.nrao.edu/memos/html-memos/alma510/memo510.pdf
----------------------------------------------------------
ALMA Memo # 511 Cycle-Slip-Free Fiber Length Stabilization System
Using a Digital Phase and Frequency Discriminator
by Yohei Sato, Mitsuru Musha, Ken'ichi Nakagawa, Ken-ichi Ueda, Akitoshi
Ueda, Masato Ishiguro
Abstract: We have developed a fiber length stabilization system (FLSS)
for the photonic distribution of LO signals by using a digital phase and
frequency discriminator (DPFD). Compared with a conventional analog
double-balanced mixer (DBM) or a phase sensitive detector with an XOR
gate (PSD), the DPFD has wider linear discrimination range by more than
1000 times, which enables cycle-slip-free FLSS. Moreover, it makes
possible to stabilize the length of the fiber that is longer than the
coherent length of the light source used in FLSS.
View a pdf version of ALMA Memo #511.
http://www.alma.nrao.edu/memos/html-memos/alma511/memo511.pdf
----------------------------------------------------------
ALMA Memo # 513 Design and Simulation of a Waveguide Load for ALMA-band 9
by F. P. Mena, A. M. Baryshev
Abstract:An important element of any waveguide-based dispositive is the
termination or load. At relatively large wavelengths the idea is to make
them as compact as possible and usually contained inside of the
waveguide. However, as the working frequency increases, the involved
dimensions make more difficult such approach. In this memo, we describe
a relatively simple waveguide load which is appropriate when the
waveguide dimensions are prohibitory small. The load described here is
rather large compared with the waveguide making it relatively easy to
realize at small dimensions. Moreover, from the results of a simulation
it is shown that besides its simplicity it can have a reflectivity as
low as -40 dB if the appropriate material is used.
View a pdf version of ALMA Memo #513.
http://www.alma.nrao.edu/memos/html-memos/alma513/memo513.pdf
----------------------------------------------------------
EVLA Memo #88 Quantization Noise
by A. R. Thompson and D. T. Emerson
Abstract:
In receiving systems in which the analog signal voltage is sampled and
quantized to allow further processing in digital form, the difference
between the analog samples and their digital representation gives rise
to a component of random quantization noise. The power spectrum of the
quantization noise is close to being uniformly level across the
receiver passband, even for large variation in the shape of the input
spectrum. Thus in cases where the gain of the analog system varies
across the passband, the addition of the quantization noise causes a
variation in signal-to-noise ratio (SNR). This effect limits the
allowable variation of analog gain and is particularly important in
wideband receiving systems. The memorandum examines the definition of
quantization noise and its relationship to quantization efficiency.
Numerical simulation is used to determine the spectrum of quantization
noise for a number of commonly used quantization schemes, with Nyquist
and higher sampling rates. Examples are given of the limiting values
of gain variation within the passband. These are modeled as slopes and
sinusoidal ripples and are applicable to the EVLA and ALMA systems.
Equations for precise calculation of quantization efficiency based on
evaluation of the quantization noise are derived in Appendix A.
View a pdf version of EVLA Memo #88 at:
http://www.aoc.nrao.edu/evla/memolist.shtml
An ALMA-specific version will be forthcoming.
*******************************ALSO OF INTEREST*******************************
SMA NEWS FLASH: First dual frequency observations - a big step for the SMA!
Simultaneous observations were made on Monday morning, JAN 24, of the
J = 5-4 transition of SiO at 215 GHz and the 1(10) - 1(01) vibrationally
excited bending mode of H2O at 658 GHz.
******************************************************************************
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 available at
http://www.cv.nrao.edu/~awootten/mmaimcal/ALMACalendars.html
More information about the mmaimcal
mailing list