SciIPT telecon 18 May 2004 John Conway, Robert Lucas, James DiFrancesco, Chris Wilson, Michel Hogerheijde, Richard Hills, Allison Sterling, Tom Wilson, Martin Zwaan, Carlos de Brueck, John Richer, Melvyn Wright, Mark Holdaway, Al Wootten Action items: Actions were updated on agenda but the list needs to be updated. Project news. Tony Beasley has accepted a position as ALMA Project Manager in the JAO. It is anticipated that he will begin serving in this position in September in Chile. Prior to this, he will be participating in various ALMA meetings. Negotiations continue with candidates for the ALMA Project Scientist position. The next Board telecon will be 27 May, with the face-to-face meeting to be held in Munich on 22-23 June. Wilson gave a report on the ASAC meeting. Tarenghi and Credland attended from the Management IPT. Antenna bids have been opened and technical study ongoing with a report due by early June. Progress on site has been substantial, with the ALMA Camp now livable--bedrooms and dining facilitites now within the camp. Kawabe gave a report from Japan (available on almaedm). Outreach was discussed. Wootten mentioned the science workshop at Md. just concluded. One thrust is to define the ARCs. In NA, the NA ALMA Science Center now has a designated head in Paul van den Bout, to begin activities 15 June. There is also a proto web page at the NRAO website. Wilson described the ESAC March meeting. Additional functions are to include: science support functions, data reductions, advanced algorithms all to be done at nodes of the aRC network at various places in EU. Call for statements of interest in mid-June. Replies by end of Sept or Oct; details under discussion. Calibration was also discussed. Prototype two load device is being defined, with a kickoff meeting scheduled at end of May for that project. Tests of the semitransparent vane are to be carried out in Madrid. The absolute calibration horn, used to measure the gain of antennas, has been deployed at BIMA and measurements at 100 GHz and 90 GHz are under way. A report has been added to the agenda. The Bandpass calibration memo has had several favorable reviews. The text is available at almaedm under Science - Documents - calibration The Calibration Plan was also presented, along with LAMA memo no. 805. Also see fs memo no. 803. Total Power gain and phase stability were presented. Further progress has been made toward understanding the effects of differential gain stability in the two polarization channels of a single receiver. Presentation at almaedm. SSR Shepherd and Lucas reported on software issues. Presentation at almaedm. System Design Review was summarized by Laing. His Presentation is at almaedm. Ops discussion was given by Silva and Emerson. Presentation at almaedm. Early Science was peresented by Wootten. Presentation at almaedm. CSV needs to be merged into Ops What modes will be available and what kind of science. Configurations: Conway reported that a Draft position calibration memo is available. The reproducibility of the axis intersection offset is a critical item. Specification felt to be somewhat arbitrary. Will finish in a week of so then apply to a reconfiguration sequence to see how the errors may mount. This duo will then result in the Plan. Look at last diagram of document. Achieving 70 microns in one axis, 30-40 in others under good conditions. However, as source gets brighter we can eventually self-calibrate. Six hours every four days would be too much. RL: Larger rms in z because you have two parameters in that--vertical coordinate and off axis intersection. They don't change in the same way. There can be an optimization done here. JC: Two reason why these coordinates are worse--scanning over hemisphere not sphere and sign in z is always constant. Extra terms like nonintersectiong axes and dry troposhper term also add complexity. On longest baselines in biggest array the dry delay needs to be well calibrated. Accurate barometers at enough places should allow us to solve for lapse rate, need 6-10 barometers well spread out across pads. RH: Are you just interested in the lapse rate close to ground or does the whole atmosphere come in. JC: Dry path delay is mostly total pressure at the ground. RH: One of the points we have been discussing is to get temp profile on the scale of the first 2-3 km. Is that relevant? JC: The dry delay is really the hydro delay. The wet delay also enters. The pressure is really most important. If we need thermal info for wet delay I have not thought about enough. JR: Obviously Radford's working group specifying the ancillary devices will be interested in this. You should be involved in our next meeting. Next meeting 1 June. Wootten briefly mentioned that within North America, the ARC first head was to be Paul vanden Bout. There is now an NAASC webpage functional. People begin arriving soon. Holdaway briefly reported on his study of polarization measurements as a function of the differential gain stability of receiver channels.The ALMA spec will not limit the science. RH: aips++ is not able to represent the ALMA polzn configuration? MH: It is unable to simulate it is all I can say. If fed real data it may or may not be able to deal with that. I think this is a small fix. N.B. This issue has been resolved. Calibration: ASAC meeting. Sterling and Hills gave an overview of the WVR work (presentation subsequently placed at almaedm ASAC presentation site). Hardware and modeling work. Sterling has just submitted a memo fulfilling a project milestone. Looks at expected sensitvitity and how it relates. DRSP: Michel reported about a dozen more estimates received. Will update before the end of June. Also make an inventory of arguments used. Imaging: Image dynamic range specification. Holdaway noted that if one considers an image at 90 GHz, in a reasonable integration one will reach 3e-5 Jy noise. 3 Jy sources could have 10^5 to one IDR. Electronics needs to be able to deal with that. Wootten to discuss with MH. SSR meeting last week. Issues being discussed are preparation for R2 October. Testing on prototype antennas. Working on software detailed requirements. Needed for review in early July. Nearly final data rate memo. ATF pointing and fast switching tests on the AEC antenna. Site: No one present to report. Continue development of ancillary devices interface documents. Ops, CSV: Operations plan G3 in final comment stage. Comments to David Silva and to Darrel Emerson please. Next meeting Tuesday, 15 June at 1430 UT. Respectfully submitted, Al Wootten