MAC Teleconference Minutes
14-APR-1999

1) Acting upon a suggestion by Larry Rudnick, it was agreed to begin keeping a standing list of action items which will remain on the MAC agenda until they have been dealt with in the form of a report or other mechanism. These action items should begin with the list of issues raised in the annual report from last November's meeting. These were (excluding antenna size and design issues):

a) A plan for deploying the remainder of the receivers after the initial three.

b) Digital FIR filter for the correlator-can the loss of efficiency be decreased to acceptable levels?

c) Phase Calibration-necessity for fast switching and implications for hardware; water vapor monitoring- 22 GHz vs 183 GHz lines.

d) Total Power Observations-requirements for receiver stability, 1/f noise, necessity for a chopping secondary, etc.

e) Array Configurations-what are the most useful configurations, especially the most compact ones? We need to understand the pros and cons better.

f) OFT Mapping, Focal Plane Arrays, etc.-we need to try to understand how often these are likely to be used and their implications for both software and hardware.

g) Testing of the Prototype Telescopes-Where, how long, and what criteria for acceptance?

h) Someone to fill the role of Mark Holdaway-It seems like the project needs someone doing the type of things Mark was doing for the project.

2) Al reported more details for the Oct. Science Meeting to be held in D.C. The meeting will be initiated with a demonstration and reception for members of Congress in the Rayburn building, room 2325 beginning at 5:30 PM on 6 Oct. (Wed). It is hoped that each of us who plan to attend will contact our Senators and Representatives and invite them to attend the reception. This will likely be more successful if the invitation is accompanied by a personal offer to explain the project, demonstrations, and equipment on display. A computer link to the 12m on Kitt Peak will be there to demonstrate remote observing. Other observatories are also welcome to set up links to their telescopes if they wish. There will be a display of the Chajnantor site, high technology parts of receivers, and documentation of radio astronomical contributions to science and technology. There may also be some room for a few posters.

The science meeting, entitled "Science with a Large Millimeter Telescope Array" will occur on 7-8 Oct. This will be an international meeting with contributors from Europe, Japan, and the US. It will be limited to 200 participants. Information on the meeting can be found at:

http://www.mma.nrao.edu/science/science99.html

The meeting will be held at the Carnegie Institution of Washington, 1600 P St. NW. Accommodations are being arranged at the Omni Shorham Hotel. A limited number of rooms will be reserved, so early reservations are advised (but not until the negotiations with the hotel are finalized).

Following the science meeting, a joint MAC/SAC meeting will take place on 9th Oct. to discuss issues relevant to both advisory committees. This will begin with a press conference at 8AM to explain the international nature of this project, its magnitude, and its scientific goals to the media and the public.

Plans for the Oct. meeting seem to be progressing very well. Al and the LOC have clearly been putting a lot of effort into this for which the MAC is very appreciative.

AS THE TIME FOR THIS MEETING APPROACHES, MAC MEMBERS SHOULD BE THINKING OF ISSUES THAT WE WILL WANT TO HAVE DISCUSSED AT THIS MEETING.

3) We can now finally rest easy at night. It is so unsettling to have a project without a name. The combined project now has an official name and acronymn. The NSF and European reps agreed on "ATACAMA LARGE MILLIMETER ARRAY" or ALMA . In Spanish, ALMA means "soul". The official naming, was achieved via a contest initiated by Bob Brown. Lots of interesting names were submitted.

4) On Mar. 30th, a meeting of the NSF and European Negotiating Teams was held in Munich. A Memorandum of Understanding (MoU) for a joint design and development program for ALMA was drawn up and initialed. This MoU, which is expected to be officially signed within a few weeks, will govern the D&D phase of the project for the next 2 years.

Management Structure
The MoU defines a management structure headed by a 12 member Project Coordination Committee composed of six members choosen by the NSF (in consultation with NRAO management) and six by the European Coordinating Committee. The project will be managed by a four member Executive Committee composed of the MMA Project Director (Bob Brown) and Project Manager (Peter Napier) and the LSA Project Manager (Dick Kurtz) and Project Scientist (Stephan Guilloteau). The Executive Committee will meet every 2nd and 4th Thursday of each month. The chair will rotate once per quarter.

Advisory Structure
A joint Science and Technical Committee and a joint Oversight Committee will be established to provide advice to both the Executive and Coordinating Committees.

Continuing Work
In the US, work will be managed by the MMA Project Team as it is now. In Europe, it will be managed by the LSA Project Team.

5) Action Items Brief progress reports were given by Al on the following items.

Amplitude Calibration:
A rapidly rotating mirrow, which alternately sees a temperature controlled load and the antenna, was installed behind the sub-reflector of one of the BIMA antennae in December. It is integrated into existing observing software and hardware, and has proven reliable since installation. It is still too early to evaluate how accurately this technique can provide amplitude calibration in routine observations, but the prospects look promising.

Water Vapor Monitor:
Andy Harris has completed construction of a 16 channel correlator module and is working on the A to D converters for reading the data out. In collaboration with David Woody, the correlator will be installed (hopefully in June) at OVRO to learn about line shapes, altitude info on the line emission, and hardware issues associated with integration into an operating system. Software is being developed by Lee Mundy and Johannes Staguhn at UMd.

Longest Baseline:
The question was raised about scientific arguments for baselines longer than the initially considered 3 km. A 10 km baseline was certainly discussed at the "Atacama Array" meeting in Tokyo. The MAC recommends that options for baselines of 10 km and longer not be precluded by hardware limitations except for reasons of technical infeasibility or prohibitive cost. Ideally, this should be limited by atmospheric effects and site limitations.

Lowest Frequency:
John Carlstrom has agreed to write a summary of the science that ALMA can contribute in the 30-45.5 GHz bands. The range of frequencies that will be covered is still under discussion, although Bill Brundage has suggested that it span the protected astronomy bands at 31.3-31.8 GHz and 42.5-43.5 GHz. The present aim is to cover the range from 30 to 45.5 GHz with sensitivity maximized at 33 GHz. This will also provide overlap with the upper frequency range of the VLA/VLBA.

The Project Book:
The final version of the MMA Project Book was scheduled to be issued on 15 April.

6) Scheduled Meetings

Holography preliminary design review (PDR) will take place on 19 Apr (today) in Tucson. The NSF MMA Oversight Committee will meet in Tucson on May 12-13. The IF System PDR will meet on 17 May in Socorro The Antenna Vendors prebid meeting will be on 18 May in Socorro THE NEXT MAC MEETING WILL BE 19 MAY AT THE USUAL TIME.

For those of you who might be interested, I have put an Excel Spread Sheet which calculates the line and continuum sensitivities for ALMA for any choice of the number and size of antennae, integration time, bandwidth, etc. This can be accessed via anonymous ftp at: 

	ftp.astro.wisc.edu
	cd /d/ftp/outgoing/ebc/ALMA

It should be opened in Microsoft Excel. All the equations etc. should appear at the top of each column if you want to change anything. I think most parameters are self explanatory by the column headings. I only caution that this was done for my own amusement and no claims for user utility or buglessness are made. If you have trouble, send me an email or give me a call and I will try to guide you through it.