Calibration Group Phone Telecon Meeting Minutes - 2003May08 Attending: Bacmann, Butler, Hasegawa, Hills, Isaak, Martin-Pintado, Richer, Wilson, Wootten, Wright (apologies to anybody I missed - Al had already initiated the telecon when I got connected, and there were a few connects/disconnects during the telecon). Agenda Minutes: - Richard summarized the document he and John produced as the (somewhat final) draft on the required ancillary calibration devices. The main remaining questions are what work remains to be done, and just who will do that work? The Science IPT and Cal Group together need to decide what needs to be done, but it is still unclear who is to do that work. It will be tied in detail to the atmospheric modelling work. Richard, in his WVR workpackage proposal, has money for a student, who *might* be able to do part of this work, but that workpackage is not approved yet, so we cannot rely on that. Juan could possibly do some of the work, but it must be coordinated and well defined. - Bryan pointed out that the ATM software was nearing availability. Juan has sent the bits of the code and it should be available on the web site soon. - Jesus summarized the new results on the S/T vane testing at the 30-m telescope. They are much more encouraging than the previous results. The main difference was that the vane was moved further from the feed. It was also thicker (4 cm), and a new material was tested in addition to the one that had been used previously. The peak-to-peak variation (varies with frequency and with day) is about 2%. The systematics are still not understood completely - there are changes with time at 3mm, and differences between the two receivers. Jesus thinks that the S/T vane system *might* get us to 2% accuracy, but it will be extremely difficult to get better than that. Butler inquired as to whether the vane filled the beam entirely. Jesus answered that it did. Richard asked whether more measurements were planned, to which Jesus replied that they were, but it remains difficult to get time on the telescope. There will be more tests in roughly one month (a couple of days), but summer is coming, and the tests will not continue beyond that. They would especially like to measure the variation as a function of elevation. Jesus pointed out that the measurement of the vane losses to the required accuracy is very difficult. - Butler summarized ALMA week activities. There was extended discussion on the WVR session. This session is still quite unsettled and there were several suggested changes to the agenda. Tetsuo suggested that we have a summary of other phase error sources. Somebody (sorry, I don't have this in my notes!) noted that the Richer+Hills review should go before the SE/FE section. Butler noted that we might want a status report on the current status at other observatories. Wright pointed out that Dick Plambeck is the right person for such a summary at BIMA. Dave Woody is the obvious candidate for OVRO and/or CARMA. There was little discussion of the calibration session agenda - most thought it was fairly reasonable. Tetsuo recommended that we add a short discussion of ACA issues. - Butler proposed the idea of a face-to-face meeting of the Cal Group late next fall or early in the winter. This would be a good time, as ATF results should be in hand, it will be after the calibration plan document deadline, and the situation with the Japanese should be cleared up. Butler will look into dates & locations. dutifully scribed by bjb on 2003May08, electronically transcribed 2003May22.