Science IPT discussion 18 August 2010. Agenda at https://safe.nrao.edu/wiki/bin/view/ALMA/18Aug10Agenda

Baltasar Vila-Vilaro, Darrel Emerson, Ed Fomalont, Al Wootten, Doug Johnstone, Jeff Mangum, Chris Wilson, (Richard Hills, Bojan Nikolic, Emily Curtis at AOS), Alison Peck, Diah Gunawan. Saito, on bus to OSF, could not join.

Welcome to Masao Saito, who joins as the Sci IPT Leader from NAOJ. Thanks to Koh-Ichiro Morita, who will be joining the new ALMA Department of Engineering as System Verification Scientist. See the announcement from Iguchi in the agenda for further information.

There are seven antennas at the AOS. The array consists of DV01 in pad N601; DV02 in pad J504; PM02 in pad T701; DV03 in pad N605; DV05 in pad J505; DV04 in pad T702; DV07 in pad J510. DV01 will travel to the OSF for some retrofitting shortly. Fringes have been seen from all 7 briefly. However, July was a tough month with disappointing progress. Problems included antenna issues of various sorts, and a major software upgrade to 7.1.1 slowed progress down also. August is looking somewhat better; there has been lots of progress during the past week. With Jeff Kern present, good progress is being made on software. There are still timing and archive issues which have been persistent.

Baltasar reported on tests on fast Total Power scanning techniques as mitigation for the late arrival of the nutator. Scanning in lissajous-like patterns is being explored on a Melco antenna. Unfortunately, the holography receiver has had some problems from a handling mishap. It is thought to be fixable on site. CV will ship new horn very soon. At the moment, a receiver is on pm03 and the campaign begins tonite.

CREs: no further discussion.

Hires: DSO archive operators on duty. Baltasar Vila-Vilaro is new DSO data management group head 1 Aug. Offers have been made for the DSO support astronomer positions. At the NAASC, one offer is outstanding. Offers were accepted by Scott Schnee and Adam Leroy. Dr Lewis Ball will be joining ALMA on 20 September 2010, via NRAO, as Deputy Director of the Joint ALMA Observatory. He joins us from Australia's Commonwealth Scientific and Industrial Research Organisation (CSIRO).

Work should begin soon on the permanent weather station at the AOS, under the guidance of Clint Janes. Richard, Bojan and Emily called in from the AOS where they reported the new station to appear to be a very suitable location. This should be complete by the end of October according to the plan.

Emily Curtis reported that O2 thermal profiler arrived last week at the OSF, and that she and Bojan arrived Monday. The instrument was unpacked and has been operating on sky. Performance seems good for early days.

The WVRs in routine ops though data quality has suffered from system timing errors.

Baltasar reported that user testing of software is coming up in a few weeks, followed by the period of reviews leading to the Early Science decision.

The ALMA staff is moving to new building on the ESO grounds beginning the end of the week. Communications may be cut briefly then. After next week, visitors should go to the new building in Vitacura; there will be no ALMA presence in Alsacia.

The future of the site testing interferometer and how the function should be provided in the future was discussed; please see words in the agenda. Richard noted that getting anything done at the AOS was difficult and that one should carefully assess and weigh effort required people and coordination needs. He asked how important continuity of measurement should be--the previous instrument operated from 1995-2009 and provided a solid database. Some sort of instrument is necessary to provide input to the dynamic scheduler. An alternative design for measuring atmospheric phase, for instance using two WVRs separated on an appropriate baseline, could be less sensitive to the dry component and comparison to the existing database might prove difficult. Emerson noted the importance of this. A group is investigating the possible change in site conditions attributable to atmospheric warming, for instance. On the other hand, there are problems with the 11.2 GHz measurements also, such as sensitivity to ionospheric effects, which may become more pronounced as the solar activity increases in the next few years.

Wootten is working on a document to summarize these factors. Hills warned that cost estimates for activity at the AOS need to have an appropriate high altitude difficulty factor applied.

Richard noted that the original goal of 8 antennas at the AOS was now projected to be accomplished at the end of the first week of September. After that, additional antennas may not arrive until December. A factor in this is that the Front End Design Verification Process will continue through the end of October, and additional front ends will be shipped after that process is complete. However, the project is on track to provide 16 antennas at the AOS by late March.

The next Science IPT telecon will occur on 15 September.

Respectfully submitted, Al Wootten

-- AlWootten - 2010-08-18