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Contact Information

  • 2007-10-17 14:30 UT Please check your local time; it may have changed!
  • Duration: 1 hr
  • USA Toll Free Number: 877-874-1919
  • Toll Number: +1-203-320-9891
  • Passcode: 185064
  • Leader: Al Wootten
  • Attendees: Wootten, Mangum, Reid, Testi, Emerson, Nyman, Morita (OSF), Lucas, Andrea, Cesar, Nikolic, Hills, Peck, Wilson, Myers, Hunter, DiFrancesco, Hales


  1. Old Business The enhanced Agenda from last meeting is available. Science IPT notes from last month's telecon are in the agenda in blue.

Melcos point Three Melco antennas are moving under ABM control. See other images and animations. See other images.

These plots were on Mercury. Darrel explains that this shows a plot of the cross-correlated phase for one of the 256 frequency channels from the spectrum (actually "channel 100") against time. The horizontal axis numbers should be multiplied by 1000 to get seconds, so this plot shows about 870 seconds of data. The vertical axis is in radians. Around 700 seconds (0.7 on the scale), you can see some of the points wrapping round 2-pi radians. The short-term deviations, particularly obvious in the first 300 seconds, are believed to be the atmosphere. I wasn't there, but I believe the weather was not very good at the time. This is just what you'd expect in mediocre weather. The linear slope over the ~850 seconds probably means we haven't got the baseline parameters quite right. I actually went out with a cloth tape measure a couple of weeks ago, and measured the relative heights and separation of the 2 antennas, as well as the approximate offset from an E-W baseline (turns out there's a 1-degree offset from exactly E-W). To compute the predicted relative propagation delay to the antennas, which I was responsible for, although I had put in a height correction, I hadn't put in the deviation from E-W. After the success on Mercury - they followed it phase stably for approximately 2 hours - they decided to try the same on a quasar, 3C279.

Darrel explains that this figure shows 4 plots, with the horizontal axes being frequency channel. There are 256 channels shown, across a 2-GHz IF band. This is from just 1 of the available 2-GHz bands in the IF. The top 2 plots are auto-correlations of the two antennas, power against frequency channel, with the vertical scale in dB. There has been no calibration applied; obviously if we were doing real astronomy, the passband shape would be calibrated out. The lower 2 plots are from the cross-correlation function. Horizontal axis the same, frequency channels (256 chans over 2 GHz). Lower left is the cross-correlated amplitude, vertical scale in dB, lower right is the cross-correlated phase, with the vertical axis in radians. The large "blip" on the left is an artificial beacon that's used in testing to help set things up. The slight linear phase slope on the lower right plot just says we haven't got the delays quite perfect, with some small fraction of a nanosecond error.
  1. New Business--Project news/updates (Wootten, Testi, Morita)
  2. Standard documents
    • Science IPT Action Items for the JAO/IPT meetings
      • Sci Reqs and Specs update for ACA? I'm not sure there are any changes needed.
      • APeck- SciIPT/DSO revised staffing profile 2008-2012, including ATF support and science fractions (DRAFT SENT)
      • DS/APeck - Investigate alignment of commissioning/calibrations hardware & software requirements with CIPT/hardware IPT plans, priorities and schedules. (UNDERWAY)
      • AWootten - Develop plan for close out of existing Site characterization equipment/ongoing monitoring. (Begun, but not urgently)
      • AWootten,RReid - Independent configuration check.: Still dragging onward. See below for Holdaway writeup. See below for Reid report.
      • RLaing: R&D required for metrology startup?? draft expected post AEM metrology mission; This is in draft.
      • JMangum: Pointing design description -- Draft submitted. Sci does not have requisite info on metrology design for AEM and Melco antennas; Vx info unreleasable.
    • Current ALMA System Block Diagram
    • ALMA Construction Picture Gallery
    • ALMA Safety Requirements
    • Photo gallery of construction events in Chile
    • Risk Register v7.0 Need to update to make current; our leaders are living in the past.
  3. Current Science IPT Schedule. Current Operations Schedule. very high level summary Schematic IPS. (2007 October 12) Cear notes: Note this time the antenna graphs do include the first Melco 12m Antenna, as well known, it is approaching Holography tests, and hence the schedule shows the expected acceptance date as of 12Dec2007. The IPS logic for Vertex antenna #2 still to be fixed once the transporter workaround is established. Also note the description for Full Science Operations and related activities now read antenna "1 thru 51", to account for the inclusion of this first Melco antenna; I will contact you directly to clarify how to nominate these activities (e.g. keep increasing the "1 thru 5x" as the Melco antennas are incorporated, or what) (in any case we are not yet prepared to include the full set of Alma J antennas until the proper integration with the associated AlmaJ electronics/deliverables are part of the IPS). The very high level summary (ipsschematic) is attached.

  1. Directories

Science IPT Group Activity Reports

Please include your Group Activity Report here (How to Enter Your Report), or email it to AlWootten

Project Scientists

  1. Science IPT -
    • Planning ATF, OSF and AOS.
      • Summary (Peck)
      • Goals (document sent around by Richard)
        • Lucas commented: My own order of priorities would be, after that:
        • 1.1) interferometric pointing JGM: We don't have synchronization now; calculation errors are now at just below an arcsecond.
        • 1.2) interferometric focus
        • 1.3) delay offsets
        • 1.4) antenna positions
        • 1.5) astr. holography
        • 2.1) temp. scale calibration
        • 2.2) line pointing and focus
        • 2.3) sky dips
      • Commissioning Scientist job postings. (Testi, Wootten)
    • Change Control Board items: Nutator specs not approved, Transporter CRE approved.
    • ATF:
      • Goals: (1) Get software working (2) Training personnel and developing procedures
      • Priorities: (1) Test (total power) functionality needed for antenna acceptance testing (2) Dynamic interferometry
        • Current total power functionality available includes (not necessarily with ALMA/CIPT software):
          • Optical pointing (Acceptance 2007-May-24)
          • holography (Acceptance 2007-May-31?)
          • focus (2007-July-2?; some hiccups thru mid-August)
          • radiometric continuum pointing (2007-Sep-12)
      • As per discussions with Alison the current schedule is below. Please let Alison and Debra know if anyone has any issues with this. During this period Simple Phase trajectory will be established and verified. Only the FLOOG will be used, no 2nd LO. Total power goals concentrate on Focus and Raster scans, Skydips. Try to move to interferometric focus, pointing during period.
Week Event
Oct 15
Myers, Hunter, de Gregorio,radiometric pointing, goal of dynamic interferometry
Oct 22
de Gregorio, Carilli: Radiometric pointing, goal of dynamic interferometry
Oct 29
Carilli, Diego Garcia: Radiometric pointing, goal of dynamic interferometry
Nov 5
Laing?, Reid: Radiometric pointing, goal of dynamic interferometry
Nov 12
Reid, Peck: Radiometric pointing, goal of dynamic interferometry

  • OSF
Week Event
Oct 22
Emerson, Peck: Holography, OPT Melco
Oct 29
Emerson, Wootten?: Holography, OPT Melco

  1. Astronomer Outreach: NRAO Newsletter New ESO, New NRAO Newsletter NAOJ News. NRAO ALMA Calendar
  2. ARC News.
  3. Group Activities (all)
  4. Next meeting is on November 21st (14:30 UT). December 19th for the following month.

Emerson/Laing/Vila-Vilaro -- Instrument Scientists

  • PSI at the ATF: Schedule, Daily Logs
  • Remijan's site to submit updates/logs/checklists for most of the procedures necessary to operate and get up to speed on the current status of the software and control systems at the ATF can be found at: ATF Updates. Please use this system at the ATF so the next member of the science IPT who arrives on site has the most recent version of the checklists and updates. Please also enter something in the daily log section! If you want a new database created for new checklists that does not fall under Science IPT Notes, contact Remijan with the title of the checklist you desire and he will add it to the site.

Holdaway, Conway -- Configuration Group

  • Holdaway's description of the development of the design for the extended ALMA configurations.
  • Eduardo Donoso and Simon Radford determined the separation between the planned ALMA antenna station A104 and the existing CBI generator plant is about 50 m. Tony Readhead and Radford agree this separation should be adequate for CBI operations and maintenance.
  • And then there were four... Array layout on the high site; weather station locations have orange dots. PDF. The Technical specifications and SOW for the IFB for the AOS Road network design have been completed. A design for road and fiber network at the high site is to be bid for construction shortly. Design of the extended array is complete; bids for antenna pad construction are out.
  • Final configuration design. We continue to assess performance (see imaging, below). We continue to assess configuration performance.
  • New <4km Configuration approved Passed CCB.
  • Proposed ACA Configuration approved.
  • ArrayCenter shows photos of the region of the center of the Array.

Jeff Mangum -- Calibration

  • Pointing Design document now drafted.
  • Calibration Plan: Current version of the calibration plan and associated documents ("examples", "roadmaps", "matrices", etc.) posted. Comments welcome.
  • Calibration Examples: The "meat" of the Calibration Plan. Review of these documents nearly complete, some need updates.
  • Ancillary Calibration Devices: Documents which describe the weather station and temperature profile technical specifications have been developed. Initial purchase documentation for (P,T,RH,Ws,Wdir) measurement devices has been made by Leonardo.

Robert Lucas -- SSR

  • Latest SSR meeting (2007-10-10).
  • ASDM changes implemented, integrated (ended last week in Socorro). ASDM freezout intended for end of year. Progresses made in finalizing common binary data format between ALMA and EVLA.
  • Software testing at ATF: single dish and simple interferometry. Fringes obtained with tracking delays (both in fine correlator and super-fine in sampler closk), as well as the phase of 1st LO; however not with final delay server yet (see plots higher on this page). Steps taken towards being able to write data in final format at the ATF.
  • Change in responsibilities as Joe McMullin leaves for Chile.

Michiel Hogerheijde -- DRSP

  • All DRSP2.0 projects have been reviewed, and responses of the authors have been collected. The findings were discussed at the ESAC and ASAC face-to-face meetings in April and May, and are summarized below.
    • Out of 149 projects from 53 authors, 42 were revised w.r.t. DRSP 1.0; 18 are entirely new; and the reminder (85) was either unchanged or no response was received (but still reviewed).
    • The distribution over science areas has not changed much.
    • Integration times were tweaked here and there, but the main uncertainty lies in including realistic overheads.
    • Quite a few projects requested cross-correlation of the 7m ACA antennas with the baseline-ALMA 12m antennas. While for some projects this is indeed essential, for most this was used only to increase the sensitivity. In terms of scheduling and operations this may be undesirable, and this needs to be reflected in the DRSP to make sure the 7m*12m is not 'overbooked'. *H
    • Once the final DRSP 2.0 projects with the authors' response included and reasoned 7m*12m requests included are added to the web site, the password protection on the latter will be removed. The details of the DRSP 2.0 will also be entered into a spreadsheet.
    • OT is almost ready to try deriving observing modes and overheads using DRSP 2.0 projects.
  • Hogerheijde presentation on DRSP2.0 to the ASAC

Richard Hills, Alison Peck, Robert Laing -- Commissioning and Science Verification

  • Commissioning and Science Verification

Steve Myers/Rob Reid (Mark Holdaway)-- Imaging

  • CASA Simulator Report
    • The Library of standard ALMA images for simulation is available.
    • Dirty beam images have been made for all of the ALMA configurations, for both snapshots and 4h exposures at a variety of declinations.
    • CASA simulation wiki with examples
    • Bojan Nikolic of the Cambridge group should soon provide a better atmospheric phase generator for the CASA simulator.

  • Pointing selfcalibration for mosaics

L.-A. Nyman -- Site Characterization

  • 21 September Radford restarted the NRAO interferometer at Chajnantor. It was a simple software glitch; a scratch directory had overflowed. His immediate goal is to see if there's a correlation between the interferometer phase fluctuations and the sky noise fluctuation seen with the Aztec and Laboca bolometer arrays.
  • Radford notes that the current phase monitoring interferometer baseline is east-west. In retrospect, it would make more sense to align it perpendicular to the direction of the satellite, about 335 deg (NW) - 155 deg (SE). Comments?
  • OSF Weather Station link.
  • In December 2006 JeffMangum submitted weather station instrumentation (RH, P, T, and wind) RFQ documentation to NRAO procurement system. After having reviewed information received from bidders and consulted with Calibration Group (see CalAncillary for discussion), on 2007/03/21 JeffMangum submitted purchase information to RobertLaing for procurement. Leonardo Testi received first set of weather measurement devices at ESO in late October. Will assemble unit at ESO for testing.
  • ICD submitted for AOS site locations discussed during August meeting. A few kinks under discussion with computing and site include power distribution (440V needs transformer) and fiber lighting (only done when antenna occupies station).The battery bank ESO2 now supplying power at the AOS will be moved to the guardhouse at the intersection of CH23 and the ALMA Road. Ulf Kaberger to implement; presumed done now but no confirmation has been received. Possible changes: phase monitoring interferometer baseline (should be 300m, not 100m) and orientation?

Remijan, Markwick-Kemper -- ALMA Working Group on Spectral Line Frequencies

Discussion of pipeline heuristics and how science advice may be incorporated.

Science Corner:

The Proceedings of the First NAASC ALMA Workshop, From Z-Machines to ALMA: (Sub)Millimeter Spectroscopy of Galaxies, has been published as Volume number 375 of the Astronomical Society of the Pacific Conference Series. A. Baker, J. Glenn, A. I. Harris, J. Mangum and Min S. Yun edited the volume.


Official JAO Calendar

ALMA Events of Interest

(see also Al's ALMA Biweekly Calendar)
Day Date Time Event location details
Oct 30-31
all day
ALMA Board Meeting
all day
Nov 7
Nov 13-15
all day
ALMA Preproduction Review
Nov 15
Calibration Group
Nov 21

Upcoming Meetings

North American URSI meeting Jan 3-6 2008, Boulder

AAS meeting Jan 7-11 2008, Austin, Tx (NRAO/ALMA booth)

IAU Symposium 251 Organic Matter in Space Feb 18-22, Hong Kong

See also NAASC listing

-- AlWootten - 11 Oct 2007
Topic revision: r15 - 2010-08-02, ToddHunter
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