Science IPT telecon. 10 Feb Michiel Hogerheijde, Wootten, Conway, DeFrancesco, Wright, Mangum, Lucas, Martin-Pintado, Robert Laing, Richer, Hills, Sterling, Aurore Bacmann, Holdaway, Hasegawa, Wootten discussed the Calendar. The major event this coming week is the mini ALMA week in Japan. Hasegawa noted that the major focus of these meetings will be to clarify the interface between JP and rest of project. PS Items are as described in the agenda. The major foci of Science IPT activity it the coming month is preparation for the System Review during mini ALMA Week. ACTION on all members of the Science IPT is to read the System Description and funnel comments to Wootten and Wilson on this so that they may be addressed during the Review. The Science IPT will also make presentations on Calibration and on Commissioning and Verification during miniALMA week subsequent to the System Review. Items discussed last telecon on the subject of the review have been addressed. A Change Request (CRE in ALMAspeak) has been submitted, as devised by Robert Lucas, to include 90d phase switching in the ALMA design. Agreement was reached on the specification for phase jitter in the design in a discussion primarily between Richard Hills and Larry D'Addario. This discussion included an exploration of the level of jitter arising in the dry atmosphere. Optical interferometers provide some data on this, for which some VLTI MIDI data was inspected. This will be quite poor during the daytime; Sterling is investigating. The optical interferometers typically operate on baselines up to 100m; it is unclear what the behavior is on longer baselines. The total power detectors can provide data on a timesample of 2msec but not shorter. While this may be adequate it is not ideal; it was noted that is seems foolish to have longer time samples than available on the correlator. Hasegawa noted that submillisec sampling should be possible and advantageous for fast scanning. ACTION: Wootten will investigate developing a specification for faster sampling. This is now 1ms in the science requirements document. Bacmann reported that passband calibration work has produced a document in memo form. This is in good shape, now working on phase calibration across the passband. Martin-Pintado reported that no time has been allocated on the 30m for further testing of the 30m vane; the amplitude calibration testing plan the Science IPT developed in Oct 2003 has not been able to proceed beyond its first item. A telecon w/IRAM is scheduled next week on how to proceed. DRSP will move to dedicated account. Hogerheijde and Wilson went through projects and selected ones suitable for ES--can they be done with 8 antennas in a reasonable amount of time? Also threw out projects which needed ACA or TP. 32 projects ended up on this first cut. Some deep integrations cannot be done. Some projects will be done-ToO, GRBs. Some items can be done with current arrays with a little bit of effort. Imaging quality not checked. Conclusion--need to distill an overview of the 32 projects to see what modes are needed, what sort of reduction might be necessary. Hasgeawa noted that in fact the TP antennas will be available Q3 2007. One only--number will increase at one per quarter. JC: how many Laing noted that DRSP polarization drivers for more stringent items missing. Would like to submit new DRSP project. This is a living document; while a general new call is not anticipated projects which use ALMA modes not pushed to their limits in the current DRSP are particularly welcome. Lucas reported that the SSR is overseeing user tests of software--full report at SSR meeting. Intermediate reports sound good. Observing Tool test reportedly successful. Offline tests have begun about two weeks ago. One activity for next few months will be refining the requirements to make them more usable for testing. Conway reported that antenna position calibration milestone making progress. 65 microns is challenging spec on baselines. Should that apply to all baselines? May be a problem in outer baselines. He can do a simulation of calibration with Monte Carlo phase screen. Need several crossing times for the turbulence on longer timescales, difficult. During most days path variations of many hundreds of microns occur. It is unclear that doing calibration immediately after antenna is moved may can result in good baselines. First, do pointing calibration during the afternoon of a move, then do first attempt at position calibration get to 200-300 microns. Observe, apply better baseline solutions retroactively for best results. Pipeline must allow capability of retroactively applying baselines. For many obs, this won't limit dynamic range very much, but options are available. Minimum number of channels needed for storing the data can be calculated. How many antennas to take and which ones? Every few weeks, full array cal. BL takes antennas from main array use the next one to be moved, then full cal occurs 64 moves. Or take nearest neighbors, which requires more often a full cal of the array. ES configurations. 6 ants poses some limitations. Need triangles of three, leapfrog out with shared baselines. That way configs with factors of three in resolution available. Most compact structure uses three antennas almost touching. How much res you need determines how many triangles. Now will find exact pads among the 172. Spatil dynamic range of any given configuration is only ~3 but combine configurations to improve this. Hills: 'It does seem to me like the triangles and moving in and out seems a good solution, fits well with ALMA whereas other arrays build up EW and use rotation to synthesize. ACTION Conway Discussion on site characterization followed. A group has formed to push development of the ancillary instrumentation at ALMA into a real requirement and specification document. This is not a funded area at present. Questions include determination of how much data can be digested at an early stage, what funding levels are necessary, and how these factors interact with ALMA's needs to suggest a staging plan for the ancillary instruments. ACTION: Ancillary instrumentation group work with Commissioning group on staging of characterization instruments. Laing: Commissioning group to put together--who would like to participate in this group? ACTION: Interested individuals contact Laing, WOOTTEN will send email to various groups inviting participation. Next meeting 9 Marcy 2004 at 1500 UT.