From awootten at nrao.edu Wed Aug 1 09:21:11 2007 From: awootten at nrao.edu (Al Wootten) Date: Wed, 1 Aug 2007 09:21:11 -0400 Subject: [asac] Telecon 1 Aug 2007 1430 UT Message-ID: <18096.35015.749981.835532@polaris.cv.nrao.edu> Folks, A reminder: Contact Information * 2007-August-1 14:30 UT * Duration: 1 hr * USA Toll Free Number: 877-874-1919 * Toll Number: +1-203-320-9891 * Passcode: 185064 * Leader: Al Wootten Agenda: https://wikio.nrao.edu/bin/view/ALMA/ASAC1Aug07Agenda After the next Board meeting the ALMA Board, and the ASAC, will go to a bimonthly schedule unless more additional meetings are wanted to fully address Charges. Please note the proposed list of telecon dates for the future: 2007 Sep 5 2007 Oct 3 2007 Nov 7 2008 Jan 9 2008 Feb f2f 2008 Mar 5 2008 May 7 2008 Jul 2 2008 Sep 2 2008 Sep f2f 2008 Dec 3 2009 Feb 4 Please note the wikis linked to the agenda for expressing your preference for the dates of the 2008 face-to-face meetings, and express yourself. Clear skies, Al +--------------------------------------------------------+ | Alwyn Wootten (http://www.cv.nrao.edu/~awootten/) | | Project Scientist, Atacama Large Millimeter Array/US | | Astronomer, National Radio Astronomy Observatory | | 520 Edgemont Road, Charlottesville, VA 22903-2475, USA | | (434)-296-0329 voice (434)-242-4713 cell | | (434)-296-0278 FAX Help us build ALMA | +----------------------------------^-----^-----^-----^---+ From awootten at nrao.edu Wed Aug 29 09:53:38 2007 From: awootten at nrao.edu (Al Wootten) Date: Wed, 29 Aug 2007 09:53:38 -0400 Subject: [asac] Correlator Modes, for Board Charges Message-ID: <18133.31330.970544.418707@polaris.cv.nrao.edu> Folks, We discussed prioritization of correlator modes at the ASAC/NA f2f meeting. The plans for the ATF and OSF now include the newly installed 2-antenna correlator, a one baseline copy of the final correlator, instead of the prototype correlator, which is now deprecated. The 2-antenna correlator, with tunable filter banks, supports more modes. Hence the interpretation of the charge from the Board is that the ASAC work on prioritization of the correlator modes. Remember that all 71 modes are listed in ALMA Memo 556. Our CSV plan calls for implementing modes which we can exercise on the 2 antenna correlator at the high site for Early Science. So please consider the questions: * Are some of the modes more desirable than others? * Are some modes not available on the 2 antenna correlator so important that they should be implemented for Early Science on the AOS correlators (this had better be a VERY strong case!!)? --------------------------------------------------------- Details What modes are available? 2-antenna correlator has modes 1-18 and 70. My presentation to the ASAC/NA is available at the agenda for that f2f meeting: https://wikio.nrao.edu/bin/view/ALMA/17Aug07Agenda as attachments at the bottom. A chat with Jim Pisano revealed to me that the correlator modes implemented by him on the prototype correlator were not those the Sci IPT recommended Aug 2005 (apparently he never got our recs; I should have sent them directly to him). But that correlator is now best used as a toaster anyway. He said: "The 2-ant correlator can do the following modes: 2 GHz, 1 GHz, 500, 250, 125, 62.5 MHz 'TFB' (modes 1-18) 2GHz 256 channels 'TDM' (mode 70) single, dual, & full polarization 2 baseband pairs 2 x 2 Bit correlations only Each TFB mode can support up to 8192 channels in single pol'n mode "The prototype correlator capabilities included: 2 GHz (256 channels), 125 MHz (4096 channels), 31.25 MHz (8192 channels) single, dual, & full polarization 4 baseband pairs The prototype correlator is capable of more modes bandwidths, but they are untested." After discussion with Jim Hesser and Ewine I interpret the ASAC charge as: Which of these myriad modes (2-ant correlator) should have highest priority. My recommendation will be the ones in the Commissioning manual which overlap the ones that the 2-ant correlator provides. That is, modes 7,12,13, 18 and 70. I think that in the ALMA Memo 556 table, the time-division mode spectral resolutions mean MHz though the column is given in kHz. I did a quick run through of the DRSP; I think this covers the resolutions most projects need whether galactic high or low resolution at low frequency or extragalactic resolution at high or low frequency. I used a few examples for the ASAC/NA and ANASAC presentations. That will leave the ASAC 14 additional modes to rank in priority if they wish. The CSV plan can then be updated to discuss the current correlator plan and ASAC recommendations. Clear skies, Al Al Wootten Interim Project Scientist ALMA, 40 El Golf, Piso 18 Las Condes, Santiago, Chile Tel: (56) (2) 467-6128 FAX: (56) (2) 467-6103 Al Wootten Cell +14342424713 From awootten at nrao.edu Thu Aug 30 22:31:53 2007 From: awootten at nrao.edu (Alwyn Wootten) Date: Thu, 30 Aug 2007 22:31:53 -0400 (EDT) Subject: [asac] ASAC Telecon Weds 5 Sept 1430 UT Message-ID: <1114.72.165.165.167.1188527513.squirrel@webmail.cv.nrao.edu> Folks, Remember please and mark on your calendar! Contact Information * 2007-September-5 14:30 UT * Duration: 1 hr * USA Toll Free Number: 877-874-1919 * Toll Number: +1-203-320-9891 * Passcode: 185064 * Leader: Al Wootten Clear skies, Al