From wilson at physics.mcmaster.ca Tue Apr 8 16:27:04 2003 From: wilson at physics.mcmaster.ca (Christine Wilson) Date: Tue, 8 Apr 2003 16:27:04 -0400 (EDT) Subject: [asac]schedule for completing written report In-Reply-To: <16008.22976.869759.271507@polaris.cv.nrao.edu> Message-ID: Hi, everyone, Here is the schedule that we agreed on at the face-to-face meeting in Grenoble next week for completing our written report: Monday, April 14: drafts of report sections due to Chris Wilson Thursday, April 17: complete draft circulated by Chris April 17-28: circulate comments on draft report; substantial comments to the ASAC email list, please (not just to me) Monday, April 28: telecon of ASAC to discuss draft report Friday, May 2: final report sent to ALMA Board This schedule is dictated by (a) my travel plans (observing, vacation, observing, ALMA Board from May 4-May 28) and (b) other people's availability around and immediately after the Easter weekend (April 18-20). If the discussion April 28 shows that people need to see a revised report before it gets sent to the Board, we can probably do that, but I'd have to finalize the report while observing (which is not ideal). The time of the telecon on April 28 is TBD, but will be near our usual time window. We just have to make sure we don't conflict with another weekly ALMA telecon. Here are the sections of the report (tied to the charges) and who is responsible for sending me a first draft: Calibration: Richer Configuration: Mundy Correlator: Bachiller Front End: van Dishoeck Software: Schilke Inhomogeneous Array: Wilson Intro, Conclusions, Executive Summary: Wilson Thanks to Ewine for already sending me the draft of her section! Cheers, Chris From soliver at nrao.edu Thu Apr 10 16:04:03 2003 From: soliver at nrao.edu (Stacy Oliver) Date: Thu, 10 Apr 2003 13:04:03 -0700 Subject: [asac][almanews] ALMA Memos 451 Released Message-ID: ALMA MEMO #451 SOME ERROR SOURCES FOR THE PWV AND PATH DELAY ESTIMATED FROM 183 GHZ RADIOMETRIC MEASUREMENTS AT CHAJNANTOR Guillermo Delgado(Onsala Space Observatory/European Southern Observatory) Fredrik T Rantakyr?(European Southern Observatory) Juan Pablo P?rez Beaupuits(European Southern Observatory) Lars-?ke Nyman (European Southern Observatory/Onsala Space Observatory) 2003/04/02 Keywords: Atmosphere, Phase variations, PWV, pathlength variations We present here an extensive study of the accuracy of the determination of the PWV from antenna measurements and in the determination of the pathlength variations (and thus phase variations). The study focussed on the effects of instrument measurement effects and software issues. We have also investigated the effect of the water vapour scale height and the presence of water vapour layers in the determination of the path delay. After correcting the software for the instrumental effects and applying empirically determined corrections to the path delay estimates we reached a good agreement between observed path delay variations and the inferred path delay variations determined from the PWV measurements. View a pdf version of ALMA Memo #451. http://www.alma.nrao.edu/memos/html-memos/alma451/memo451.pdf Download a postscript version of ALMA Memo #451. http://www.alma.nrao.edu/memos/html-memos/alma451/memo451.ps _______________________________________________ Almanews mailing list Almanews at listmgr.cv.nrao.edu http://listmgr.cv.nrao.edu/mailman/listinfo/almanews From wilson at physics.mcmaster.ca Fri Apr 11 15:04:55 2003 From: wilson at physics.mcmaster.ca (Christine Wilson) Date: Fri, 11 Apr 2003 15:04:55 -0400 (EDT) Subject: [asac]schedule for completing written report In-Reply-To: Message-ID: Hi, everyone, Please don't forget that the deadline for submitting draft sections of the report is Monday, April 14 So far I have received sections on the receivers from Ewine and on software from Peter and Lee. Please don't be late, as I have only two days to put the whole thing together if I am going to circulate it before European members leave their offices for the Easter long weekend on Thursday. Thanks, Chris From awootten at nrao.edu Mon Apr 14 16:20:48 2003 From: awootten at nrao.edu (Al Wootten) Date: Mon, 14 Apr 2003 16:20:48 -0400 Subject: [asac]Re: ASAC Agenda In-Reply-To: <16003.32010.659848.390472@polaris.cv.nrao.edu> References: <16003.32010.659848.390472@polaris.cv.nrao.edu> Message-ID: <16027.6176.818716.4134@polaris.cv.nrao.edu> Dear ASAC Presenter: The ASAC appreciates the presentation you made at the ASAC meeting last week. Thanks very much for agreeing to do this. A folder has been established at ALMAEDM for deposit of the presentations so that the ASAC may consult them during the writing of its report. Please deposit presentations at: http://almaedm.tuc.nrao.edu/forums/alma/dispatch.cgi/almaprojmeetings/folderFrame/100527/0/def/9d3e Thanks, 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 Help us build The ALMA| | (434)-296-0278 FAX {> {> {> {> | +----------------------------------^-----^-----^-----^---+ From ldaddario at nrao.edu Mon Apr 14 15:58:01 2003 From: ldaddario at nrao.edu (Larry D'Addario) Date: Mon, 14 Apr 2003 12:58:01 -0700 Subject: [asac][almanews]ALMA Memo 452 is available Message-ID: <3E9B12C9.23A805A2@nrao.edu> ALMA MEMO #452 Passband Shape Deviation Limits Larry D'Addario (NRAO) Dated 2003/04/09 Submitted 2003/04/14 Keywords: passband calibration specifications Abstract: Beginning with the ideal passband, which is constant from Nf_s/2 to (N+1)f_s/2 and zero elsewhere, where N=0,1,2,... is the Nyquist interval number for sampling rate f_s, we examine the effect of deviations from that form on radio telescope performance. The implications for both continuum and spectroscopic observations are considered. Among the deviations of interest are: finite band edge slope, leading to non-zero response outside the Nyquist interval (aliasing); gain slope across the passband; gain ripple across the passband; and mismatch of the responses among antennas in an array. When analog filters are involved, the variation of response with temperature is also a consideration. Most of this report is applicable to radio telescopes in general, but numerical examples are selected for relevance to the ALMA telescope and specific recommendations for ALMA are given. Download a PDF file of ALMA Memo #452: http://www.tuc.nrao.edu/~ldaddari/alma/memo452.pdf _______________________________________________ Almanews mailing list Almanews at listmgr.cv.nrao.edu http://listmgr.cv.nrao.edu/mailman/listinfo/almanews -- ============================================================ Larry R. D'Addario Research Engineer National Radio Astronomy Observatory, Tucson, Arizona, USA 949 N Cherry Ave, Campus Bldg 65 7711 E Linden St University of Arizona Tucson, AZ 85715 Tucson, AZ 85721-0655 tel: +1/520/882-8250 x123 +1/520/885-8240 fax: +1/520/882-7955 Email: ldaddario at nrao.edu ============================================================ _______________________________________________ Almanews mailing list Almanews at listmgr.cv.nrao.edu http://listmgr.cv.nrao.edu/mailman/listinfo/almanews From tetsuo.hasegawa at nao.ac.jp Wed Apr 16 01:50:49 2003 From: tetsuo.hasegawa at nao.ac.jp (Tetsuo Hasegawa) Date: Wed, 16 Apr 2003 14:50:49 +0900 Subject: [asac]Band 4 frequency extension Message-ID: Dear ASAC members, At the ASAC meeting in Grenoble, I was asked to consult with the Japanese frontend development team about the possibility of extension of the Band 4 frequency coverage up to 185 GHz to cover the water line. Below is a quick reply from Yutaro Sekimoto, leader of the Japanese frontend group. Answer: Although it is an interesting development target, it would be very difficult to extend the RF frequency range of Band 4 that much, given the time schedule for fixing the design. It is even more true because we are aiming at using 2SB mixers that relies on the waveguide technology. Even if it becomes possible, significant degradation of the receiver noise temperature and image rejection ratio would be unavoidable. Frequency coverage of the multiplier for LO would be another serious problem. For your reference, below is a list of fractional frequency coverage specified for the ALMA receiver bands. Band f(center) f(low) - f(high) coverage 1 35 GHz 30 GHz - 40 GHz 29% 2 79 GHz 67 GHz - 90 GHz 29% 3 100 GHz 84 GHz - 116 GHz 32% 4 144 GHz 125 GHz - 163 GHz 26% <<< current spec. 4* 155 GHz 125 GHz - 185 GHz 39% <<< if extended 5 187 GHz 163 GHz - 211 GHz 26% 6 243 GHz 211 GHz - 275 GHz 26% 7 323 GHz 275 GHz - 370 GHz 29% 8 443 GHz 385 GHz - 500 GHz 26% 9 661 GHz 602 GHz - 720 GHz 18% 10 869 GHz 787 GHz - 950 GHz 19% With best, Tetsuo -- _______________________________________________________________ Tetsuo HASEGAWA, D. Sc. ALMA-J Project Scientist Professor, National Astronomical Observatory of Japan 2-21-1 Osawa, Mitaka, Tokyo 181-8588, Japan Phone +81-422-34-3780 / FAX +81-422-34-3764 _______________________________________________________________ From guillote at iram.fr Wed Apr 16 09:15:28 2003 From: guillote at iram.fr (Stephane Guilloteau) Date: Wed, 16 Apr 2003 15:15:28 +0200 Subject: [asac]Band 4 frequency extension References: Message-ID: <006501c3041a$4094cbe0$d78353c3@Guilloteau> 185 GHz is certainly quite far, and it would cause also problems for the LO settings. However, it would be good to check whether the H2S line at 168.8 GHz could be reached. It is only 6 GHz away from the current nominal upper band limit. This would be useful for chemistry. Stephane ----- Original Message ----- From: "Tetsuo Hasegawa" To: Cc: ; Sent: Wednesday, April 16, 2003 7:50 AM Subject: [asac]Band 4 frequency extension > Dear ASAC members, > > At the ASAC meeting in Grenoble, I was asked to consult with the > Japanese frontend development team about the possibility of extension > of the Band 4 frequency coverage up to 185 GHz to cover the water > line. Below is a quick reply from Yutaro Sekimoto, leader of the > Japanese frontend group. > > > Answer: > Although it is an interesting development target, it would be very > difficult to extend the RF frequency range of Band 4 that much, given > the time schedule for fixing the design. It is even more true > because we are aiming at using 2SB mixers that relies on the > waveguide technology. Even if it becomes possible, significant > degradation of the receiver noise temperature and image rejection > ratio would be unavoidable. Frequency coverage of the multiplier for > LO would be another serious problem. > > For your reference, below is a list of fractional frequency coverage > specified for the ALMA receiver bands. > > Band f(center) f(low) - f(high) coverage > > 1 35 GHz 30 GHz - 40 GHz 29% > 2 79 GHz 67 GHz - 90 GHz 29% > 3 100 GHz 84 GHz - 116 GHz 32% > 4 144 GHz 125 GHz - 163 GHz 26% <<< current spec. > 4* 155 GHz 125 GHz - 185 GHz 39% <<< if extended > 5 187 GHz 163 GHz - 211 GHz 26% > 6 243 GHz 211 GHz - 275 GHz 26% > 7 323 GHz 275 GHz - 370 GHz 29% > 8 443 GHz 385 GHz - 500 GHz 26% > 9 661 GHz 602 GHz - 720 GHz 18% > 10 869 GHz 787 GHz - 950 GHz 19% > > > With best, > > Tetsuo > -- > _______________________________________________________________ > Tetsuo HASEGAWA, D. Sc. > ALMA-J Project Scientist > Professor, National Astronomical Observatory of Japan > 2-21-1 Osawa, Mitaka, Tokyo 181-8588, Japan > Phone +81-422-34-3780 / FAX +81-422-34-3764 > _______________________________________________________________ > _______________________________________________ > Asac mailing list > Asac at listmgr.cv.nrao.edu > http://listmgr.cv.nrao.edu/mailman/listinfo/asac From awootten at nrao.edu Tue Apr 22 10:16:51 2003 From: awootten at nrao.edu (Al Wootten) Date: Tue, 22 Apr 2003 10:16:51 -0400 Subject: [asac]AIPS++ Consortium Ends Message-ID: <16037.20179.283418.512192@polaris.cv.nrao.edu> AIPS++ Consortium Ends The members of the AIPS++ Consortium, the National Radio Astronomy Observatory, ASTRON, the Australia Telescope National Facility, the Jodrell Bank Observatory, and the Berkeley-Illinois-Maryland Array, announce the end of the consortium, effective immediately. The end of the consortium means the withdrawal of the resources currently committed, the end of joint management meetings, and the end of the consortium executive. The AIPS++ code base generated by the consortium remains available to all. The code base is covered by the GNU Public License, held by Associated Universities. At this juncture, we would like to summarize the accomplishments of the consortium. Although our shared goal of developing the next generation radio astronomical data reduction software package has not been fully realized, the package does have the basic core capabilities for radio astronomy and has been used in various targeted applications. However, the Executive Committee has concluded that the consortium structure is no longer appropriate as we turn from building the core of the package to developing scientific applications targeted to our specific telescopes. Consequently, future collaboration between our observatories will be in the form of new bilateral or multilateral agreements and will focus on specific scientific needs. The AIPS++ Executive Committee wishes to recognize all those who have contributed to the project over its entire lifetime. We thank all of the many very talented and dedicated people have been involved in the project in many different ways. We assure these people in particular that the core capabilities of AIPS++ will not be lost - as described above, we expect that future developments by our individual observatories will make appropriate use of the extensive functionalities in the AIPS++ package. The AIPS++ Executive Committee: Harvey Butcher, Tim Cornwell, Dick Crutcher, Phil Diamond, Ron Ekers, and Fred Lo (Chair) April 21, 2003 From soliver at nrao.edu Tue Apr 22 11:24:26 2003 From: soliver at nrao.edu (Stacy Oliver) Date: Tue, 22 Apr 2003 08:24:26 -0700 Subject: [asac][almanews] ALMA Memos 454 Released Message-ID: ALMA MEMO #454 Total Power Observing with the ALMA Antennas Jack Welch (UC Berkeley) April 2003 Particularly at the shorter wavelengths, the ALMA will need to do mosaic observing to cover large fields of view. Along with the mosaic pointing, there will need to be total power maps to fill in the interferometric short spacings and produce complete images. It is well known that this is best done with a single antenna that is two to three times the diameter of the interferometer antennas. However, that will not be possible for ALMA; there are no 24m - 36m antennas available that will work well to 0.35mm wavelength. As long as a mosaic of pointings is employed in the interferometry, a single antenna map made with one of the interferometer antennas will suffice in principle. This is rarely done, largely because the interferometer antennas are not usually equipped to do it. This capability must be in place for the ALMA antennas. How it is best done may be studied with the prototype antennas. View a pdf version of ALMA Memo #454. http://www.alma.nrao.edu/memos/html-memos/alma454/memo454.pdf _______________________________________________ Almanews mailing list Almanews at listmgr.cv.nrao.edu http://listmgr.cv.nrao.edu/mailman/listinfo/almanews From soliver at nrao.edu Tue Apr 22 16:06:40 2003 From: soliver at nrao.edu (Stacy Oliver) Date: Tue, 22 Apr 2003 13:06:40 -0700 Subject: [asac][almanews] ALMA Memos 453 and 455 Released Message-ID: ALMA MEMO #453 An Integrated Sideband-Separating SIS mixer Based on Waveguide Split Block for 100GHz Band Shin'ichiro Asayama (Osaka Prefecture University/Nobeyama Radio Observatory), Hideo Ogawa (Osaka Prefecture University), Takashi Noguchi (Nobeyama Radio Observatory), Kazuji Suzuki (Instrument Development Center of School of Science, Nagoya University), Hiroya Andoh(Toyota National College of Technology), Akira Mizuno(Solar-Terrestrial Environment Laboratory, Nagoya University) April 2003 We have been developing an integrated sideband-separating SIS mixer at 100\ GHz based on waveguide split block. The measured single-sideband (SSB) receiver noise temperatures with L-band IF ($f_c$ = 1.5\ GHz ) are less than 60\ K in the LO frequency range of 90--115\ GHz, and minimum >value of around 35\ K is achieved at 100\ GHz. The image rejection ratios are more than 11\ dB in the frequency range of 90--110\ GHz. We have installed the sideband-separating SIS mixer into an atmospheric ozone measuring system at Osaka Prefecture University and successfully observed an ozone spectrum at 110\ GHz in SSB mode. This experimental result indicates that the sideband-separating SIS mixer is very useful for astronomical observation as well as atmospheric observation. View a pdf version of ALMA Memo #453. http://www.alma.nrao.edu/memos/html-memos/alma453/memo453.pdf ------------------------------------------------------------------------------------------------- ALMA MEMO #455 Cartridge Test Cryostats for ALMA Front End Y. Sekimoto, T. Kamba, S. Yokogawa, M. Sugimoto, T. Okuda, R. Kandori, K. Tatematsu, K. Muraoka, A. Ueda, T. Nishino, N. Okada, T. Fukuda, K. Kaneko, H. Ogawa, K. Kimura, K. Noda, K. Narasaki, and K. Suzuki April 2003 We have developed four cartridge test cryostats for ALMA FE cartridge-type receiver with taking account of reliability and easy operation. It uses a simple, compact and efficient thermal link between a cartridge-type receiver and a plate connected to a 3 stage Gifford-Mcmahon (GM) cryocooler. The cooling time of the cartridge-type receiver is less than 10 hours. With a cartridge loader, a cartridge-type receiver is easily inserted and extracted in a condition that the cryostat is closed. View a pdf version of ALMA Memo #455. http://www.alma.nrao.edu/memos/html-memos/alma455/memo455.pdf _______________________________________________ Almanews mailing list Almanews at listmgr.cv.nrao.edu http://listmgr.cv.nrao.edu/mailman/listinfo/almanews From awootten at nrao.edu Thu Apr 24 11:45:12 2003 From: awootten at nrao.edu (Al Wootten) Date: Thu, 24 Apr 2003 11:45:12 -0400 Subject: [asac]Meeting Monday 28 April 2003 (NOTE DAY, TIME) Message-ID: <16040.1672.377551.139734@polaris.cv.nrao.edu> Folks, There will be an ASAC telecon on Monday, 28 April 2003 at 1530 UT. CALL TIME: 11:30 AM EASTERN Daylight TIME 1530 Universal Time CALL DATE: 28-April-2003 (Monday) DURATION: 1 hr * USA Number: 877-874-1919 * Outside USA Number: +1-712-934-1791 * Passcode: 185064 * Leader: Al Wootten Agenda at: http://www.cv.nrao.edu/~awootten/mmaimcal/asac/asacapr03agenda.html will grow with time... 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 Help us build The ALMA| | (434)-296-0278 FAX {> {> {> {> | +----------------------------------^-----^-----^-----^---+