ALMA Science Advisory Committee

19-20 March 2002

Mitaka, Japan

Draft Minutes

Participants: R. Bachiller, G. Blake, R. Booth, L. Bronfman, R. Brown, Y.

Chikada, T. Cornwell, P. Cox, C. Cunningham, N. Evans, Y. Fukui, P. Gray,

S. Guilloteau, T. Hasegawa, M. Ishiguro, R. Kawabe, R. Kurz, J. Mangum, D.

Mardones, H. Matsuo, N. Nakai, M. Rafal, J. Richer, S. Sakamoto, P.

Schilke, Y. Sekimoto, P. Shaver, K. Tatematsu, M. Tsuboi, E. van Dishoeck,

M. Walmsley, W. Wild, A. Wootten, S. Yamamoto, M. Yun

G. Blake welcomed all participants to this face-to-face meeting of the

ASAC. The proposed agenda and plan for writing the report were accepted.

1. Project Update

M. Rafal summarized the project status. In the U.S., $12.5 million are

already available for construction in FY 2002, and NSB approval is expected

shortly on the complete construction project. For FY 2003 the President's

budget requests $30 million for continued construction funds. An inflation

projection of 3.6% p.a. is assumed. In Europe, construction approval is

expected in July, and the proposal foresees a slower ramp-up in funding

than in the U.S. This difference in the funding profiles is one of the

issues the AEC is currently dealing with. M. Rafal mentioned major upcoming

events, including the ACC meeting on 18-20 April (major items Phase 2 plans

and the International Project Office) and ALMA week on 23-27 April at which

there will be over 100 participants and both plenary and parallel sessions.

R. Kurz gave an overview of the baseline project scope and schedule. The

first production antenna should be on the site in the 4th quarter of 2005.

By the end of 2006 there will be seven antennas, and science commissioning

will begin. In the 4th quarter of 2007 interim science operations should

begin. The overall schedule has been extended by one year, to 2011. R.

Booth asked when the central project office will be staffed, and R. Kurz

replied that the applications are coming out now.

2. Current Project Status in Japan

M. Ishiguro summarized the current status of the project in Japan. The ASTE

10-meter antenna has been completed and moved to the 4800-meter Pampa la

Bola site. It is currently being equipped with its SIS receivers and

spectrometer, and the infrastructure is being developed. The 12-meter

prototype has been approved, as has a new building at Mitaka, which will

include the SIS fabrication facility. The 12-meter prototype is due to be

delivered at Socorro in April 2003. It will have the same specs as the

European and U.S. prototypes, and will weigh 80 tons. Negotiations with

MEXT and the Ministry of Finance are continuing for participation in the

global ALMA project by FY 2004 or earlier.

3. Project Status in Chile

R. Brown and L. Bronfman gave an overview of the project status in Chile. A

"direct concession" to a Chilean entity is being considered, which may be

managed by a "concessional committee". Aspects of site protection were

discussed. The proposed location of the OSF at 2800 meters altitude was

described. It will not be too far from San Pedro, and staff will have the

option of living in San Pedro rather than at the OSF.

4. Prototype Antennae Update

M. Rafal described the progress with the U.S. prototype. Delivery is

expected in July. Concerning the European prototype, R. Kurz said the

amended contract had been signed on 18 December 2001, with what is now an

Alcatel/Costamasagna/EIE consortium. The final design will accommodate the

Media Laurio panels; these have a surface accuracy of 6.6 microns,

consistent with an overall 20 micron rms surface accuracy. M. Ishiguro said

that the Japanese 12m prototype will have a surface accuracy of 20 microns

rms and pointing accuracy of 0.6 arcsec. Delivery is due in Socorro in

April 2003.

5. Revised Testing Program in Socorro

J. Mangum summarized plans for testing the prototype antennas. All three

evaluations should be completed by 1 January 2004. They will be done by an

Antenna Evaluation Group (AEG), and an Antenna Evaluation Working Group

(AEWG) will be comprised of an extra pool of members. No prototype

frontends will be used for the evaluation of the prototype antennas. He

said that interferometer and spectroscopic measurements may not be used to

evaluation the prototype antennas; interferometry can improve the results,

but is not essential. The interferometer would later be used to test the

software and system. The decision on the contractor is due in October 2004,

and then it will be about one year to the first production antenna. The

goal is one final design, although there could be several contractors.

6. Prototype Receivers and LO

W. Wild reviewed progress on the prototype receivers. He reported on work

at IRAM on the optics and alignment at IRAM (completed), and work on the

windows and calibration (three types are being tested). The cryostat

development work at RAL received the go-ahead at the September 2001

meeting. He reported on work underway on band 7 (IRAM DSB, OSO 2SB) and

band 9 (NOVA/SRON), the IF amplifier development (SRON, Yebes, Chalmers),

and the water vapour radiometer (MRAO, OSO). C. Cunningham reported on the

progress in North America on bands 3 and 6. R. Booth and S. Guilloteau

stressed the emphasis on sideband separation up to 350 Ghz. S. Guilloteau

said that 4-8 Ghz sideband separation may be adequate (as opposed to 4-12

Ghz). E. van Dishoeck stressed the importance of the stability of the

receivers. To her question about the first production receivers, W. Wild

said that there were too few people available for timely completion. N.

Evans suggested that a complete review of the production issue may be

needed by the next ASAC meeting.

7. IF Subsystem and Baseline Correlator

P. Gray, the new N. American system engineer, gave a status report on the

backend and correlator. Major milestones in the schedule are completion of

the backend (12/03), the correlator prototype (10/03), and the final

quadrant (10/07).

8. Calibration, WVR System

A. Wootten reported that a Calibration Group has been formed, led by the

Project Scientists (A. Wootten and S. Guilloteau). R. Lucas is the liaison

between the SSR and the Calibration Group. R. Booth suggested that liaison

with the people on site (L.-A. Nyman and others) was also desirable . A

prototype of the semi-transparent vane system (IRAM) will go to the

prototype antenna. The dual load calibration system (BIMA) is now being

built at NRAO. There is no report yet on the standard gain horn (BIMA).

Concerning phase calibration, a 183 GHz WVR is being tested on the SMA,

and a 22 Ghz radiometer at OVRO. IRMA will be installed at Chajnantor in

mid-2002. There are many PDR actions.

The issue of bandpass calibration was discussed by S. Guilloteau - the

options of the noise source through the subreflector, and the

semi-transparent vane system. The latter will be prototyped at IRAM and

tested on the test interferometer. Regarding atmospheric transmission

modeling, there is now a model good to 2% over the range 0-2 Thz, and an

implementation technique is required.

9. Options for Proposal Review Committees

N. Evans said that there was a preference to refer to a "Proposal Review

Committee" rather than a "TAC". Two alternative concepts were considered in

detail: subject-based and partner-based PRCs. P. Shaver asked in what

language proposals would be written in Japan; T. Hasegawa replied that they

would be in English if there were more (Asian) partners with Japan. R.

Bachiller asked whether it would be necessary to account for individual

member countries within the ALMA partners (eg. Europe). P. Shaver commented

that this is not done, for example, by ESO. The concept of stringency was

discussed, and whether high stringency time should count the same as low

stringency time. The dynamic scheduler was also discussed; it could include

partner parity over a long enough time scale. S. Guilloteau commented that

legacy programmes, like the HDF, must be done. It was realized that the

report could avoid making a specific recommendation for a particular type

of PRC, as all could be made to work; the important point is that the

policy requirements are satisfied in the most efficient way. There was

further discussion on the principles and use case, and general agreement on

the principles. The point was made that the simulator will do most of the

technical assessment. The question of how to account for staff observing

time remains an issue. Generally it was agreed that time should be counted

in accordance with the partner membership of the PI of a proposal, but

there was the additional question of whether co-Is should be counted also.

N. Evans summarized the outcome of the discussion and recommendations.

Recommendations to the ACC on partner parity will be: decouple parity from

the PRC method (the dynamic scheduler helps here); consider

stringency-weighted time; and allow different ways to count the time (coIs

may be included). Recommendations to the project: work with the ASAC to

define stringency more precisely; and assess the statistics of stringency

at the site (considering such long-term effects as El Nino). Y. Fukui

commented that more time should be spent on legacy projects, and P. Shaver

added that there would be strong support for this from the wider community.

10. Overview on RSC Core Functionalities

The core functionalities were generally agreed to comprise user support

(assistance with observation preparation, data reduction, and archival

research), feedback on performance, and hosting the archive or a copy of

the archive. Questions concerned the overlap with Virtual Observatory for

archival research, whether the archive should be a physical copy or just a

link, and the relation to the SOC. Y. Fukui felt that software development

should be considered a core function. Whether or not that is the case, it

was agreed that software development has to be part of ALMA, and has to be

funded. Concerning the SOC, P. Cox said its responsibilities were not yet

defined. L. Bronfman said it would be useful to Chile to add core

functions to the SOC. E. van Dishoeck commented that the SOC should be

responsible for the pipeline and quality control, and users get data

products directly from the SOC/OSC/Observatory. N. Evans said that an RSC

is not a SOC. P. Cox commented that the RSCs provide feedback to the SOC.

11. European Presentation on RSCs

P. Cox gave a summary of discussions concerning the European RSC. It would

provide day-to-day support. For development work, it would be a strong

central node in a European network, and external funds would be required

for non-core activities.

12. Japanese Presentation on RSCs

Y. Fukui said that in Japan there already was a central body (NAOJ); the

core functionalities would be similar, but should also include software

development. Other possible activities of the RSC were suggested: updating

(including the archive), promoting science with ALMA (eg in summer

schools, hosting meetings). 10 FTEs were considered a reasonable maximum.

L. Bronfman said that in Chile the core functions could be carried out in

Santiago (or at the OSC); added functionality would be to transmit science

and education to the country. D. Mardones commented that RSCs may not

really be needed - except for non-radio astronomers, those working

predominantly in other (eg. optical/IR) wavebands.

13. North American Survey Results

N. Evans summarized discussion in North America. There would be just one RSC for the N. American partner countries. Added functions would include software support

and outreach. Providing financial support was very important; software

development had a lower priority. The location should be near an air hub,

more convenient than the present NRAO locations. It should be operated by

NRAO. The FTEs are estimated in the range 10-40, at 50/50

functional/scientific work. Astronomers should be able to access any of

the RSCs. T. Hasegawa asked where all the upgrades for ALMA would be done.

R. Brown replied that there is a a draft operations plan; the Director

directs the observatory and its local and partner-supplied staff; the

partners are the executives, and they provide the upgrades, both hardware

and software.

14. AIPS++ testing report

S. Guilloteau gave a report on the testing of AIPS++ for off-line

processing of ALMA data. The goals are (1) to see if it can be suitably

adapted, (2) to know how long the learning curve is, and (3) to do an end

to end experiment on actual mm spectral data. The status so far is that the

exchange format has been received and accepted, the data set has been

selected, and the data set results have been transferred from IRAM to the

AIPS++ team. The AIPS++ adaptation has been found to be OK. There is no

answer yet on the end to end experiment on actual mm data, but there are no

obvious show-stoppers. If the tests are successful, AIPS++ can be used as

a basis for ALMA data reduction.

15. NRAO Data Management Plans, including the end-to-end product

T. Cornwell described the data management plans at NRAO. The effort started

in May 2000, and will result in a large improvement in data services for

the user. It includes the management of AIPS++, and the management of

computer services and policy. It will streamline observer access, and

greatly improve the data products and the archive. It is an "end to end

(e2e) project", involving 65 FTE-years over about five years. It is new

territory for NRAO, and will use a "spiral development model". There are

many similarities to plans for ALMA. The connectivity was stressed between

NRAO and the National Virtual Observatory. There will be a pipeline and

archive facility document. T. Cornwell commented that an important

consideration is that experts are location dependent - they cannot easily

be moved, so inter-site collaboration should be encouraged.

16. Baseline receiver bands production report, Europe and N. America

In introducing this topic, W. Wild commented that ALMA will need 512-1152

SIS mixers, compared with 200 currently operating in the world today. He

gave a summary of issues for mass production. He emphasized that it is

important to learn from space programmes, and to test receivers on the

Chajnanaor site. The objective is to have a receiver run for one year

without problems. C. Cunningham mentioned as examples the specific cases of

bands 6 and 9 production. There are many sources for the various

components for each receiver. These would come to receiver integration sites, one of which would be at Tucson. There would be automated receiver test sets for each

receiver. "Repair" will involve on-site replacement by a "hot" unit. The

faulty unit will be taken to the OSC, so at least some aspects of the

receiver test set must be there.

17. Receiver production report, Japan

Y. Sekimoto gave an overview of the receiver production plan in Japan. He

mentioned the quality control issues, the major technical issues, the test

equipment, and the pre-production engineering model including on-site

evaluation with ASTE. He described a new facility that will be built at

NAOJ for ALMA, which will include a clean room, assembly room, etc.

G. Blake asked all three speakers when we need critical items in order to

get the receivers on time. The answer was this year. J. Mangum stressed the

need to have the receivers on site on time. R. Brown said that the antennas

and receivers will be done in synch. S. Yamamoto commented that

interferometry should be done as soon as possible. S. Guilloteau said that

it will be important to have at least one receiver with every cartridge for

tests.

18. Results of Configuration CDR, Imaging Performance

A. Wootten reviewed the Configuration CDR that took place on 24-25 January

2002. Highlights included an elegant design theory developed by Boone (and

used now for the Allen array), sidelobe optimization techniques by Kogan,

the Delannay u-v optimization elaborated by Webster, and the hybrid u-v and

beam optimization elaborated by Conway. Ampngst the action items:

appointment of a leader; appointment of a consulting engineer; high

resolution imagery and maps; a report and update at the forthcoming "ALMA

Week"; a site development PDR in September; and a complete configuration

design by January 2003. Various options are still under study for the

compact configuration, and the intermediate and large configurations. A

possible Y-shaped configuration for 8-9 km baselines is under

consideration, which includes antennas along the OSF road. L. Bronfman said

that it was important to know what "exclusive areas" are needed for ALMA

(outside areas may be shared with other possible projects).

19. Towards a 3-way ALMA

R. Brown reviewed the evolution of plans for the project since last

October. At that time the ACC had requested details for the baseline

project. There is now a simplified WBS, which is far better than before.

The costs are under control, and it shows the scope of the baseline project

and the overall schedule: 4Q 2002 - agreement signed with Chilean

government; 3Q 3002 - RfP released for production antennas; 4Q 2004 -

antenna contract(s) awarded; 4Q 2005 - first production antenna at the OSF;

4Q 2006 - start of science commissioning operations; 4Q 2007 - start of

interim science operations; 2011 - all antennas on site. Japanese entry

into the project will provide the enhancements. M. Ishiguro said that, in

order to have a 3-way project in 2004, a budget proposal was required

before August 2003. A draft agreement is needed, specifying what Japan

should provide. At the ALG meeting on 18 March 2002 it was stressed that

close collaboration between the three partners is necessary on many

aspects: overall project planning, antenna evaluation, 2G correlator

coordination, and frontend/LO photonics development coordination. S.

Guilloteau commented that the configuration already allows Japanese

participation. The priority list is clear, but M. Ishiguru expressed the

view that if the ACA is a necessary Japanese contribution, it should be

pushed to the highest frequencies. T. Hasegawa said that he would

eventually like the ASAC to make a recommendation/endorsement for a model

for Japanese participation. Y. Fukui said that there should be a lot of

interaction with the project and with ASAC before June 2003. T. Hasegawa

outlined a schedule involving working group meetings in April, June,

September, and December.

20. Preparation of Reports

Following meetings of the sub-groups, the group leaders presented outlines

of their draft reports for comments and discussion.

The report sections are as follows:

Project status, management: from minutes

Site issues, configuration: Booth, Bronfman, Sakamoto

ACA simulations, science: Cox, Crutcher, Hasegawa, Welch

Correlator: Bachiller, Scoville, Yamamoto

Operations: Evans, Fukui, Wilson

Software: Benz, Gurwell, Tatematsu

Calibration, WVR: Matsuo, Richer, Wilson

Polarization: Crutcher

Receivers: Blake, van Dishoeck, Nakai

Antennae, test interferometer: Fukui, Walmsley, Welch

ASTE, APEX: Kawabe/Yamamoto, Schilke

21. Election of new Vice-Chairperson

G. Blake announced that C. Wilson will be the next North American

vice-chairperson of the ASAC.

22. Next Teleconference and Meeting

The next teleconference is scheduled for Wednesday April 3, at the usual

time.

The next face-to-face meeting is tentatively scheduled for September 2002

in Socorro.