The third meeting of the NSF and representatives of the participating
organizations in Europe
collectively known as the European Negotiating Team, led to the initializing of a
MOU for design
and development of a joint, large millimeter/submillimeter array. The five (5)
European
organizations are: (1) the European Southern Observatory (ESO); (2) the French
Centre National
de la Recherche Scintifique (CNRS); (3) the German Max-Planck-Geschellschaft (MPG);
(4) the
Netherlands Foundation for Research in Astronomy (NFRA); and (5) the UK Particle
Physics and
Astronomy Research Council (PPARC). The MOU will take effect as soon as it is
signed by all
parties and it will expire on December 31, 1999, or on the date that an agreement
for the
construction phase of the joint project is signed. A joint project Coordination
Committee will be
established upon initiation of the MOU; the Coordination Committee is to be
comprised of six
representatives named by the NSF and six named by the European organizations.
Management of
the joint project is the responsibility of an Executive Committee made up of the MMA
Project
Director and Project Manager and the LSA Project Manager and Project Scientist. The
Executive
Committee is assigned the task of producing a Project Work Program and Management
Plan in
120 days for approval by the Coordination Committee. Two joint advisory committees
will be
appointed by the Project Coordination Committee. These are a Science and Technical
Advisory
Committee and an Oversight Committee. The former is expected to subsume the present
US
MAC and European SAC.
In late February a meeting was held between the MMA Division Heads and
counterpart
representatives of the LSA project. The goal of the meeting was to identify ways in
which the
two groups could effectively collaborate on the tasks needing to be accomplished in
the design
and development phase of the joint project. Time was spent reviewing what is being
done for the
MMA project and reviewing resources and interest among the European groups in tasks
to
augment that effort. The report of this meeting is available on the MMA web pages.
A highlight
of the meeting was the desire of all the technical groups for access to a test
interferometer to be
made up of one antenna supplied by the US and the other supplied by Europe. The two
antennas
are to be prototypes from different contractors. Such an approach has the advantage
of
permitting a comparative evaluation of the two prototypes and of keeping competition
in the
antenna procurement process through the prototype phase.
The February meeting was very timely in that the US RFP for the prototype antenna
was nearing
the date of its release. The meeting allowed several remaining specifications to be
established or
refined. The US RFP was issued to contractors on March 30 with responses due in
three months.
The European request for tender, using the same technical specifications as are in
the US RFP, is
expected to be released approximately one month later. The US and European groups
will
collaborate on their respective bid evaluations so that the two prototypes come from
different
contractors.
Finally, the joint array project needed a name. Suggestions for a name were solicited via an emailing to all those receiving the MMA electronic newsletter and similar groups in Europe. A list of approximately 30 suggested names was circulated in the same manner as a straw ballot. An ordered list of the "top ten" names receiving votes was presented to the NSF and ENT groups at their March 30 meeting. These bodies agreed on the name Atacama Large Millimeter Array (ALMA) for the joint project. The acronym ALMA is a Spanish word meaning soul. Thanks to all who participated by means of their suggestions and votes.
The transition from MMA to ALMA has begun with every prospect that the remaining
three
quarters of 1999 will be as eventful as the first.
R. L. Brown
The advent of high stability, long coherence length lasers has made possible a
round trip
correction system for the distribution of the local oscillator ( or a reference
signal) based on the
actual wavelength of 1.5 microns. Such a system holds the promise of overcoming
changes in the
length of the fiber distribution system due to both thermal and mechanical effects.
Engineers
W. Shillue and A. Viccari have demonstrated such a system over a round-trip
distance of 2 km
over 1 km of fiber. A closed loop servo system is used to hold the path length
constant to a few
tens of nano-meters. This system uses all commercially available components and
should
completely compensate for all changes in fiber length.
The final application being investigated is the feasibility of injecting a
photonically generated
signal directly into the receiver at the signal frequency. This application requires
orders of
magnitude less power than the generation of the local oscillator and, when combined
with the
correction system mentioned above, raises the possibility of a complete
instrumentation
calibration.
J. M. Payne
L. R. D'Addario
The purpose of the conference will be to highlight the science that this powerful world array will accomplish, with a particular focus on:
It will begin with a reception and demonstration for members of Congress in the
Capitol at 5:30
p.m. Wednesday, October 6, 1999.
Lectures and posters will be presented at the Carnegie Institution of Washington,
1600 P St. NW
on October 7 and 8. Accommodations have been arranged at the nearby Omni Shoreham
Hotel
for the period including the nights of October 5 through October 9.
A press conference will begin the proceedings to explain the world collaboration
to the media.
This will be held in the Board Room of the Carnegie Institution of Washington at
8:00 a.m. on
October 7.
The conference will be organized and hosted by Associated Universities, Inc., and
the National
Radio Astronomy Observatory. The Scientific Organizing Committee is composed
of John
Bieging, Geoff Blake, Roy Booth, Bob Brown, John Carlstrom, Ed Churchwell, Ewine van
Dishoeck, Neal Erickson, Neal Evans, Yasuo Fukui, Stephane Guilloteau, Mark Gurwell,
Tetsuo
Hasegawa, Richard Hills, Masato Ishiguro, Ryohei Kawabe, Gill Knapp, Karl Menten,
Jim
Moran, Steve Myers, Naomasa Nakai, Luis Rodriguez, Larry Rudnick, Peter Schloerb,
Peter
Shaver, Jean Turner, Malcolm Walmsley, Eric Wilcots, Al Wootten (Chair), and Satoshi
Yamamoto.
"Science with a Large Millimeter Array" will be limited
to 200 participants. Information will be
posted on the Millimeter Array web site with the URL
http://www.mma.nrao.edu/scienc
e/science99.html.
H. A. Wootten
Connecting the Backup Structure (BUS) to the Box
The installation of the permanent supports on the BUS was completed in December,
and the work
is now focused on the BOX supports and connecting beams. As of mid-March the rework
on all
but two of the Box supports has been completed, and 26 of the 30 permanent support
beams are
in place. All of the materials necessary to complete the permanent support system
have arrived in
Green Bank from the fabricator in Texas. Inspection of the welding on the remaining
Box
supports will be completed by the end of March, after which the support beams will
be installed.
The permanent supports are scheduled to be completed by the middle of April.
The program of removal of the temporary supports has begun. The first temporary
chosen is one
in the center of the structure, surrounded by three installed permanent supports.
Removal of most
of the temporary supports must await completion of the permanent supports.
Installation of the Vertical Feed Arm & the Upper Feed Arm
COMSAT has continued to review the procedure for completing the installation of
the Vertical
Feed Arm (VFA), and has modified the order in which the tasks occur, so that more of
the
welding is done on the ground where it is easier and better controlled. The welding
of the
intermediate VFA modules K and L is now complete. Selected members of the
transition module
M will be fitted and bolted to the completed module L on the ground. Other members
of M will
be bolted to the Upper Feed Arm, and then the Upper Feed Arm will be trial-assembled
to KL,
again on the ground. Because the alignment of the Upper Feed Arm will be done under
controlled conditions on the ground, rather than with the structures suspended from
cranes in the
air, it is anticipated that the process will proceed much more rapidly. Moreover,
this modified
procedure ensures that the Vertical Feed Arm will fit well, and will be properly
aligned with
respect to both the VFA and the vertex of the dish.
Installation of the Feed Arm will be completed by raising the welded modules KL and the bolted module components M, installing the transition module J between H and K, raising and attaching the Upper Feed Arm, and welding the members of module M. It is anticipated that the entire Feed Arm will be completed by the end of May.
Other Activities
Although the principal focus continues to be on the permanents and the Feed Arm,
COMSAT is
making progress in other significant areas. The effort to install shim packs and to
align the
elevation gear segments is about one-third complete. Servo engineers from Precision
Control
came in March and continued the installation of the permanent drive controls in both
azimuth and
elevation. And the long process of providing the electrical distribution on the
structure is nearing
completion.
Major activities anticipated for the late spring are the resumption of the alignment of the actuators and the final installation of the actuator cables. The actuator alignment will begin after the load of the backup structure has been transferred to the permanent supports, and the work on the cables can begin shortly thereafter.
The Surface Panels
Work on the GBT panels is continuing at the RSI facility in Sterling, VA, with
good progress. In
March, 11 measurements of the panels from three more tiers were forwarded to NRAO
for
evaluation. The panels, 158 in number, are from tiers 22, 24, and 31. They were
accepted in an
inspection visit to Sterling, Virginia on March 19. At this time, 1683 panels
have been assembled
and 834 have been measured and accepted.
The installation of the robotic painter was completed after some delays, and the
machine has been
successfully checked out. Selected panels from tier 26 were painted with the new
system and the
paint coats passed the evaluations for uniformity, thickness, and adhesion. RSI
reports that 98
panels have now been painted.
R. D. Hall and D. E. Hogg
No further proposals for observing time on the 140 Foot, other than filler-time
requests for blocks
on the existing schedules, are being accepted. The proposal queue will virtually
be emptied by
July 26 and will include the completion of some long-running survey projects.
A technical group within the Observatory is studying decommissioning options for
the 140 Foot.
P. R. Jewell
For PC users, the Windows NT server in Green Bank is fully operational. It is
used to serve
common software packages to all users, including AutoCAD, the Corel suite, and
MicroSoft
Office. Public PCs served from this are available to visitors.
For low volume data, observers can now take their data away on CDs. We have
re-writable CD
drives installed on a public NT computer and a public Linux system.
We hope to have a superior internal network in the Jansky Lab to support the GBT
when it is
operational. In particular, we need to be able to support 100 Mbps Ethernet between
modern
PCs and Suns. Rather than risking the unwanted radio emissions from twisted pairs,
in 1998 we
purchased fiber to replace the thinwire Ethernet in the old Jansky Lab. This will
be installed when
we purchase the associated Ethernet switches.
The Observatory submitted a successful proposal to the NSF Computer and
Information Sciences
and Engineering (CISE) directorate for an upgrade of the Intranet at the major four
sites to full
T1 (1.544 Mbps). This will provide a 3-4 fold improvement in access to the Internet
from Green
Bank. In addition, the grant will provide video conferencing capabilities between
the sites and
with the community.
G. C. Hunt
An ARISE information booth was set up at the American Astronomical Society
meeting in
January 1999, complete with scale models of an inflatable antenna and of an
inflatable strut that
would connect the antenna to the spacecraft. The executive summary of the ARISE
science goals
and the first version of the spacecraft and mission study were available at the
booth. We
anticipate that a more detailed science document, and a more complete second edition
of the
mission design book, will be available some time in April 1999.
During February 1999, the ARISE mission concept was presented to the radio panel
of the
Astronomy and Astrophysics Survey Committee ("decade committee") and to the
Structure and
Evolution of the Universe Subcommittee (science advisory group to one of NASA's
space science
themes). Recommendations of the decade committee will be completed by early 2000,
while the
revision of the strategic plan for NASA's Office of Space Science is due in
mid-2000. We hope
that ARISE will figure prominently in both sets of recommendations.
Minutes of the NRAO/JPL meeting, or copies of any of the ARISE literature, are
available from
the undersigned.
J. S. Ulvestad
J. D. Romney
M. J. Claussen
Regular gain determinations of VLBA antennas are made only at standard
frequencies in each
band; these frequencies are listed in the vlba_gains.key file. Noise-diode
strengths used to
compute system temperatures and gains may not apply at other frequencies, which can
affect the
initial calibration at frequencies far from the standards. Particularly at risk are
Faraday-rotation
programs and VSOP observations, both of which often use frequencies far from the
standards.
Noise-diode strengths at 6 cm for Saint Croix (LCP) and Los Alamos (RCP and LCP)
below
4900 MHz appear to have been far from the assumed values since at least December
1997.
Typical high-elevation system temperatures should be near 40 K, whereas the reported
values for
these antennas may be as low as 30 K or as high as 60 K.
We remind observers that the overall calibration should always be checked by
observing an
amplitude check source and assessing the consistency among antennas. If frequencies
far from the
standards are used, observations of a check source should be made at both the
standard and
non-standard frequencies, to detect any offsets in the calibration values. Many
users have not
been following the recommended procedure of including such calibration checks in
their
schedules, and therefore have not had the means to correct for offsets. For
information on
amplitude check sources, see the section on amplitude calibration in the VLBA
Observational
Status Summary, at http://www.nra
o.edu/vlba/obstatus/obssum.vlba/obssum.vlba.html.
We currently are seeking better means of testing for calibration offsets and of
warning users of
non-standard frequencies much more forcefully. For further information about the
calibration
issues described above, please contact the undersigned at julvesta@nrao.edu.
J. S. Ulvestad
| Date | Bands |
Proposals Due |
| 27 May to 17 Jun 1999 | 6 cm, 18/21 cm, 3.6/13 cm | 01 Oct 1998 |
| 09 Sep to 30 Sep 1999 | 6 cm?, 5 cm?, 18 cm, UHF | 01 Feb 1999 |
| 12 Nov to 03 Dec 1999 | 6 cm?, 5 cm?, 18 cm, 1.3 cm | 01 Jun 1999 |
The bands above marked with a question mark have been suggested, but the final
choice has not
yet been made.
It is recommended that proposers use a standard cover sheet for their VLBI
proposals.
Fill-in-the-blanks TeX files are available by anonymous ftp from ftp.cv.nrao.edu,
directory
proposal or via the VLBA home page on the web. Printed forms, for filling in by
typewriter, are
available on request from Lori Appel, AOC, Socorro.
Any proposal requesting NRAO antennas and antennas from two or more institutions
in the
European VLBI network constitutes a Global proposal. Global proposals MUST reach
BOTH
Network's Schedulers on or before the proposal deadline date; allow sufficient of
time for mailing.
In general, fax submissions of Global proposals will not be accepted. The Socorro
correlator will
be used for some EVN only observations unsuitable for the Bonn correlator until such
time that
they can be processed with the JIVE correlator. Other proposals, not in EVN
sessions,
requesting use of the Socorro correlator must be sent to NRAO even if they do not
request the
use of NRAO antennas; proposals for the use of the Bonn correlator must be sent to
the MPIfR if
they do not request the use of any EVN antennas.
For Global proposals, or those to the EVN alone, send proposals to:
R. Schwartz Max Planck Institut fur Radioastronomie Auf dem Hugel 69 D 53121 Bonn Germany |
For proposals to the VLBA, or Global Network proposals, send proposals to:
Director National Radio Astronomy Observatory 520 Edgemont Road Charlottesville, VA 22903-2475 USA. |
Proposals may also be submitted electronically, in Adobe Postscript format, to
proposevn@hp.mpifr-bonn.mpg.de or propsoc@nrao.edu, respectively. Care should be
taken to
ensure that the Postscript files request the proper paper size.
B.G. Clark
Please visit our new control room in person, or view it on the VLA
web page at,
http://www.nrao.edu/~lbrother/cru.html
,
P. D. Hicks
| Configuration | Starting Date | Ending Date | Proposal Deadline |
| D | 05 Mar 1999 | 01 Jun 1999 | 1 Oct 1998 |
| A | 18 Jun 1999 | 27 Sep 1999 | 1 Feb 1999 |
| BnA | 08 Oct 1999 | 25 Oct 1999 | 1 Jun 1999 |
| B | 29 Oct 1999 | 14 Feb 2000 | 1 Jun 1999 |
| CnB | 25 Feb 2000 | 14 Mar 2000 | 1 Oct 1999 |
| C | 18 Mar 2000 | 30 May 2000 | 1 Oct 1999 |
| DnC | 09 Jun 2000 | 26 Jun 2000 | 1 Feb 2000 |
The maximum antenna separations for the four VLA configurations are: A-36 km,
B-11 km, C-3
km, D-1 km. The BnA, CnB, and DnC configurations are the hybrid configurations with
the long
north arm, which produce a round beam for southern sources (south of about -15
degrees
declination) and extreme northern sources (north of about 80 degrees declination).
|
Approximate Long-Term Schedule | ||||
| Q1 | Q2 | Q3 | Q4 | |
| 1999 | C,D | D | A | B |
| 2000 | C | C,D | D | A |
| 2001 | B | B,C | C | D |
| 2002 | A | A,B | B | C |
| 2003 | D | D,A | A,B | B |
Observers should note that some types of observations are significantly more
difficult in daytime
than at nighttime. These include observations at 327 MHz (solar and other
interference; disturbed
ionosphere, especially at dawn), line observations at 18 and 21 cm (solar
interference),
polarization measurements at L-band (uncertainty in ionospheric rotation measure),
and
observations at 2 cm and shorter wavelengths in B and A configurations (tropospheric
phase
variations, especially in summer). They should defer such observations for a
configuration cycle
to avoid such problems. In 1999, the B configuration daytime will be about
18h RA and the C
configuration daytime will be about 2h RA.
Time will be allocated for the VLBA on intervals approximately corresponding to
the VLA
configurations, from those proposals in hand at the corresponding VLA proposal
deadline. The
VLBA spends about half of available observing time in coordinated observations with
other
networks, with the scheduling dictated by those networks. In decreasing order of
the time
devoted to the observations, these are HALCA space VLBI, Combined Millimeter VLBI
Array,
Global astronomical VLBI with the EVN, and geodetic arrays coordinated by GSFC.
Any proposal requesting NRAO antennas and antennas from two or more institutions
affiliated
with the European VLBI network is a Global proposal, and must be sent to the EVN
scheduler as
well as to the NRAO. VLBA proposals requesting only one EVN antenna, or requesting
unaffiliated antennas, are handled on a bilateral basis; the proposal should be sent
both to NRAO
and to the operating institution of the other antenna requested. Coordination of
observations with
non-NRAO antennas, other than members of the EVN and the DSN, is the responsibility
of the
proposer.
B. G. Clark
With assistance from New Mexico Tech, the computer room located on the main floor
of the
AOC has also been renovated with partitions. This area will provide office space to
students who
work at the AOC, including students from New Mexico Tech and NRAO summer students.
J. F. Dowling
The installation of the 14 Pentium II 400 PCs running the Linux operating system
which were
purchased in late 1998 is almost completed. Although most of the tools and
applications available
on Suns under Solaris have equivalent counterparts under Linux, there are still
areas in which
Linux is somewhat deficient. In such cases we are putting effort into finding
workable
alternatives.
The AOC computing department continued to phase out Arana, its aging Auspex file
server.
Arana has provided NFS service such as operating systems, home accounts and binaries
for the
AOC for the past eight years. Arana also acted as a mail hub, license server, YP
server and
administrative server. Arana is currently being replaced by a new Network Appliance
Filer 720
called Filehost. Filehost will take over all NFS duties from Arana. To date
Filehost has taken
over all system level file systems including operating systems and binaries. By the
end of March,
home accounts and any remaining file systems should be moved to Filehost. Zia, a
SPARC 20,
will take over Arana's mail hub and administrative duties.
With the decommissioning of Arana, the AOC was recently able to complete the
redesign of its
network topology, making it far more flexible. This has made it possible to easily
move machines,
particularly laptops. Reconfiguration of the network or replacement of aging
equipment is now a
much simpler matter than before and requires virtually no rewiring.
It was decided that the scope of the new VLA online system should include the
requirements of
the upgraded VLA. Originally, this project was started with the aim of replacing
the aging
Modcomp computers with modern hardware. Now this has been considerably widened to
include
the upgraded VLA as well. This means the project will take longer: five-six years
instead of the
original three-four. We expect to have end user and high level systems requirements
documents
available later this year. We expect the Array Support Group to closely communicate
and
cooperate with their equivalent in the MMA project, which should lead to similar use
of computer
languages and operating systems, and sharing of code libraries wherever expedient.
G. A. van Moorsel
Topics include:
The conference will be organized and hosted by the National Radio Astronomy
Observatory. The
Organizing Committee is composed of Philippe Andre, Darrel Emerson, Mark Gordon,
David
Hogg, Phil Jewell, Harvey Liszt, Jeff Mangum (chair), Simon Radford, Goeran Sandell,
and Al
Wootten. The proceedings from this conference will be published in the Astronomical
Society of
the Pacific (ASP) Conference Series. For further information regarding registration
and
accomodations, see http://www.tuc.nrao.edu/imaging99.
J. G. Mangum
These documents can be accessed from the 12 Meter Telescope web page at
http://www.tuc.nrao.edu/otherdocs.html
.
J. G. Mangum for the Tucson Staff
We invite all 12 Meter Telescope users to subscribe to this list server. To
subscribe to 12mnews,
send the following in the body (not the subject line) of an email message to
"Majordomo@majordomo.cv.nrao.edu:" subscribe 12mnews
This will subscribe the account from which you send the message to the 12mnews
list.
If you wish to subscribe another address instead (such as a local redistribution
list), you can use a
command of the form: subscribe 12mnews
other-address@your_site.your_net
If you have questions or comments about 12mnews, please let me know.
J. G. Mangum
This appointment will make it possible for Bob Brown to focus all of his time on
the Millimeter
Array Project and the growing activity that accompanies the merger of the Millimeter
Array with
the Large Southern Array. I am delighted that Tony has accepted this appointment,
and I look
forward to working with him.
P. A. Vanden Bout
The Observatory is also taking steps which we hope will significantly improve our
wide-area
connectivity, probably via access to vBNS and/or Abilene ("Internet2"). To this
end, we are
exploring arrangements with the universities to which the major NRAO sites have, or
can get,
fiber connections, with a view to increasing the bandwidth of our WAN connections.
Possible
applications include real-time data transfers to other institutions on these
high-speed networks
from NRAO telescopes, including the 12 Meter, the VLA, and the GBT, as well as
better access
to archival data and to the high-performance computers at the NCSA.
M. R. Milner
How to run it: On any workstation running Solaris or
Linux type: jobserve and a window will
appear that will bear some resemblance to the old observe layout. The major
difference is that the
key-bindings have been replaced by a point-and-click interface.
How to get help: From the help menu choose Help (or
type Ctrl-H), and a help window will
appear with a list of topics to choose from.
How to report problems: E-mail your problem report or
any other kind of feedback to jobserve.
G. A. van Moorsel
The main disadvantages of FITAB are:
I encorage people to use the task and let me know if there are problems.
E. W. Greisen
Press releases generally need to be prepared and distributed some time prior to
publication or
presentation of the research result. This is done even when journals, such as
Nature and Science,
have strict policies about advance publicity. In these cases, the press release is
distributed to
journalists under a publication embargo, meaning that they cannot publish or
broadcast a story
until the time specified on the release. This arrangement allows journalists to
interview the
researchers and prepare their stories in advance. When an embargoed press release
about your
work has been distributed, it is perfectly all right to talk with journalists who
have received it. It
is wise, however, to remind them of the embargo at the beginning of the
conversation.
A press release can be issued by NRAO, by the observer's home institution, if not
NRAO, or by
both. Generally, the press officers of both the Observatory and the observer's home
institution
should be notified of upcoming newsworthy publications. Many professional journals
issue
advance notices to the media, often under embargo, promoting interesting papers in
upcoming
issues. We routinely coordinate advance press releases with these journals.
Usually, the time to start talking to your press officer, whether at NRAO or
another institution, is
at least as soon as your paper is accepted. When representatives of journals or
professional
meetings warn you against advance publicity, they do not mean that you should not
talk to
institutional press officers. Preparing a press release and distributing it so as
to maximize the
media exposure for your research requires substantial lead time.
Finally, please remember to give credit to NRAO and the NSF for results of
research on NRAO
instruments, both in your paper and when talking to journalists. The official
credit statement for
acknowledgment in papers is: "The National Radio Astronomy Observatory is a
facility of the
National Science Foundation, operated under cooperative agreement by Associated
Universities,
Inc."
D. G. Finley