First VLBI2010 Working Meeting

September 15, 2006
MIT Haystack Observatory

Overview    Keynote    Format    Participants

   Agenda    Logistics    Discussion Papers


The primary function of the VLBI2010 Committee (V2C) is to promote and guide research into the improvement of the "technique" of geodetic VLBI. The committee takes an integrated view of VLBI and evaluates the effectiveness of proposed system changes based on the degree to which they improve IVSís final products. In addition, the committee takes responsibility for encouraging the implementation of the recommendations of WG3. Please find more information on the V2C homepage.


The most urgent issue facing the V2C is the definition of specifications for the VLBI2010 antenna. This is needed to support current proposals for new geodetic VLBI antennas in Australia, Korea, Germany, and possibly elsewhere. There is risk involved in the process because the favoured method for determing the delay observable, the "S-Ku broadband delay" approach, has never been tested. Although plans exist to test it, results are not anticipated for at least a year. The focus of this meeting will be to study the "S-Ku broadband delay" approach theoretically to see whether or not enough confidence exists to use it as a basis for determining the VLBI2010 antenna specifications.

Briefly, the "S-Ku broadband delay" approach involves the use of a large number of IF bands to unambiguously determine the RF phase. It requires the use of a broadband feed such as the Kildal feed, and opens up the possibility of determining the very precise phase delay even at modest SNRs. Complicating factors, which need to be studied, include the effect of source structure, non-linearity and instability of the feeds/electronics/ cables, RFI, and possibly others.

Although other topics relating to improvement of VLBI results will be considered for this meeting, they will only be included if time permits.


The format of the meeting will be similar to that of the East Coast VLBI Meeting that many of you attended last year. A number of short informal presentations will be made. These are not intended to be polished final reports, but simply works in progress. They will be used as a stimulous for discussion. The presenter will then moderate discussion on that topic.

The time for each presentation and discussion will be flexible so that the depth of treatment can reflect interest and perhaps the diversity of views.

Prior to the meeting it is expected that written summaries of the work to be presented will be distributed so that attendees can be better prepared with questions, comments and ideas for the following discussion.


There are currently 31 participants registered for this meeting. Please notify the Coordinating Center if you detect an error in the list of participants.


We anticipate a long event, with the working meeting starting early and ending late. The draft agenda outlines the topics and their approximate times. The actual times, however, will be dependent on the evolution of the meeting.


The First VLBI2010 Working Meeting is an add-on to the Fifth International e-VLBI Workshop and shares the logistics of that meeting. Please refer to the e-VLBI meeting page for hotel and travel information. There is no registration fee, but the cost for food will be shared among the participants. There will be breakfast, lunch, coffee breaks, and a full dinner—all being served at Haystack Observatory. Please be prepared to pay $55 at the meeting. Notify Heidi Johnson if your plans change, so that amendments can be made.

On September 15, we will meet in the lobby of the Sheraton Tara Hotel, Nashua, NH at 7:30 a.m. in order to organize the car pooling to Haystack Observatory.

Discussion Papers

Please find here the discussion papers for the meeting:

Session 1: Goals of Meeting and Simulations

  • V2C Simulations at IGG Vienna (Joerg Wresnik, Johannes Boehm): PDF
  • Simulations at GSFC Using Solve (Dan MacMillan): PDF

Session 2: Source Structure, Schedules, and Multiple Antennas

  • UV Coverage of New High Density Schedules (Toni Searle): PDF (4 MB)
  • Source Structure Examples (Arthur Niell): PDF
  • The Effect of Selected Sources on Broadband Delay Performance (Bill Petrachenko): PDF
  • Multiple Antennas at a Site (Bill Petrachenko): PDF
  • Number of Sources (Arthur Niell): PDF

Session 3: Electronics

  • Notes on broadband feeds (Brian Corey): PDF
  • Polarization issues (Brian Corey): PDF
  • Notes on phase/delay stability of cable and electronics (Brian Corey): PDF
  • Simulations of Broadband Delay Measurements (Alan Rogers): PDF
  • Calibration of Broadband Geodetic VLBI (Alan Rogers): PDF
  • Notes on cable length measurement systems (Brian Corey): PDF
  • Clock and Calibration for VLBI2010 (Tom Clark): ppt

Session 4: Troposphere, RFI, and EVN Plans

  • RFI Scope and Reduction Approaches (Gino Tuccari): ppt
  • A Simple Approach to Handling RFI (Bill Petrachenko): PDF