Science IPT Telecon 10 June 2003 Hasegawa, DiFrancesco, van Dishoeck, Testi, Wootten, Richer, Mangum, Martin, Butler, Cernicharo, Tatematsu, Shaver, Bacmann, Lucas, Guilloteau, Gueth, Morita, Wilson, Pardo, Wright, Pety Old: Action items: Bandpass calibration document coming; standing waves delivered. Cal doc to be commented upon by PS by week's end. By next meeting to all. Data rate report. Richer--very nearly distributed before ALMA Week interrupts. After ESAC meeting. New version by 16 June. Milestones: List updated. Major Milestones in June are 9812 and 9815 due on 30 June. These are the science requirements flowdown document and the Y+ configuration document. Project News and updates: News--delay in approval of ESO/Chile. Temporary permit to open road should be granted. Charges - Special Board telecon pretty soon to consider possible charges for ASAC. Guilloteau Comments on calibration at ALMA Week. Not much time for serious discussion. There was a presentation on capabilities of amplitude calibration. Lamb presented a different way using a dielectric material rather than a grid; could replace grid, less predictable but easier to use. Welch on dual load device showed the standing wave problems are higher than expected but basically it does not work; we should put in a change request. Standing wave memo is on the website. What sort of cone do we want in subreflector? Short bandpass cal presentation Emerson and Payne tests on strong emitter at subreflector. Diode with high power at high frequencies. Absolute calibration scheme as enhanced by Guilloteau. Interesting point should be followed up. May be possibilities in Europe to develop such a system. Phase calibration item. Semitransparent vane in a new position offers better repeatability. D'Addario memo on gain stability; it will be difficult to have stability better than few times 10-4 which may have consequences on polarization calibration. Combining effects of gain and amp cal problems accuracy may be better than 2% and stability better than 10-3. Worries about polarization capability. WVR: Richer. Requirements and status; file to almaedm. Nothing significantly new was presented, rather this was a summary of requirements and specifications and whether more scientific validation was required or useful. At the ATF using the interferometer one could do tests, which particularly offers the chance to test interfaces and so on. But there isn't much phase to correct on 35m baselines, and the test interferometer may be dismantled soon after it is assembled. What decisions were made? RH: more of a challenge to correct the small errors on short baselines. We just push the sensitivity. This would test a lot of the methods. Hills: When is there an interferometer at the OSF. SG: Baseline not longer than 100m or so. Richer: other places where validation may be possible each have showstopping issues. SG: This is true and would make additional effort. RH: More than doubling the effort. Action items: Wobbler. Do we need it or not? Current design is to give space and to accommodate one, budget for nutator and cal device. If we do not need any nutator we can have a lighter subreflector, which is significant saving on couterweight, antenna center of gravity etc. RH: I have always been very conscious that one of the most difficult specs is the absolute pointing spec of 2". Why do we need that? This is a pretty strong driver and we may wish to alter this. SG: We must be careful as we don't want the offsets in the absolute pointing model to be to large. Design reference mission: Plan circulated last night to help us to determine the array of instruments we need and how the science we plan affects this and the staging of the array to completion, design of software, calibration and other items. What would three years of ALMA observing look like? * Should apply only to full array * Baseline ALMA project only for the moment. Option to suggest benefits to project by ACA. * Overview more important than microview. Focus on broad high priority projects. * Cover all science themes in a fair balance, starting with the science case. BB: Make a direct link to the document easier to find. 4 themes, 20 subthemes, about the same number as with the JWST. * People to be responsible for assembling information for subtopics suggested; please accept or scream to Ewine. BB: Person identified for each theme or just subthemes? EvD: PS probably responsible for themes; SG: we may not need to be completely exhaustive to achieve the goal of having main modes covered. EvD: Some subthemes may be done very quickly but should still have placeholders as they may drive some items. BB: How do these overlap with use cases from SSR? We should borrow from what they have done. SG: There is not really an overlap; we don't want detailed use cases, just what we need on calibration, modes etc. Lucas: but there is no frequency of occurrence in the use cases--how often do we need wide field mosaicing etc is not covered. TH: Important to check whether we have covered major modes, e.g. polarimetry, we should pick whether we have good coverage with our final mix. EvD: some of the science examples for calibration for example should be covered. EvD: Please agree or offer to take lead within the week, or suggest alternatives? Science statistics: Fraction of time allocated to a certain team must be watched over, as TAC would do in practice. Some sort of prioritization should occur; ASAC may want to take a look at this. CW: I agree, but the methodology is unclear to me. EvD: We need a rough breakdown first, perhaps from the PS. ASAC may come in for second round of this. We'd like to have a first go at this before the face-to-face meeting. We need to agree on sensitivities, ESO calculator on the WWW site. This has been double checked so this should be used. SG: Careful when you use polarization. The list of setup parameters should be quite general. Observing modes should agree with SSR lists. RL: dynamic range should also be considered in point 4. LT: Also one should think about Phase II requirements. BB: Also include total size of source to understand requirements as other observing parameters (will drive choice of mosaic or not). Frequency may be needed also in addition to just band. SG: We should make a template and circulate it. CW: We should consider polarization as a separate obsering mode rather than just another observing parameter. EvD: Actually I thought of this as a separate subtheme; I'll discuss with you offline. Specifications: Don't give source lists. Need to know if specific RA ranges are critical as this may affect operations. Supply first draft of each section by mid-August. JP participate in this task. What shall we do if we are to add bands 8, 10 and 4. We address deep submm via band 9 now, which unfortunately does not include [C I]. SSR: Meeting tomorrow; see the schedule. Need input on interim operations. Configuration: Need to provide some early information on extended configurationa asap. Conway to shortly finish on move sequence. ACA report from Hasegawa describes the science case and how that drives the system design. It is still a draft, with feedback from the science IPt needed by July. Eventually this will be an element of a detailed JP proposal. The document goes far beyond the configuration, which we are still working on. We have a question on declination coverage--this should be addressed by science IPT. 24 June action item. Imaging Relatively premature, correction for decorrelation is one item. We may need some coordinated effort to see how we are gong to include this decorrelation. Wobbling secondary also to go into this group. Gueth looking into OTF interferometric mode, to do some exploration of this with PdBI. IAU -- New movies, simulations, and other material. Madsden in DC next week. ACTION: ALL ACA feedback by July Declination coverage feedback due 24 June Configuratio group. Data rate document 16 June. Richer Milestones: Y+ Configuration submitted 2003-June-30 Holdaway Science Requirements submitted 2003-June-30 Butler Bandpass calibration document. Bacmann, Guilloteau Design Reference Science Plan - Project Scientists, E. van Dishoeck, lead Wobbler: Redesign? Imaging group, Gueth, lead.