Summary Notes from the Seventh IVS Directing Board meeting Tsukuba, Japan, February 3, 2002, 0900-1730 Notes by N. Vandenberg Attending: K. Kingham, A. Whitney, A. Nothnagel, H. Schuh, Y. Koyama, N. Capitaine, S. Matsuzaka, E. Himwich, A. Niell, C. Ma, N. Vandenberg, W. Schlueter, W. Cannon, B. Corey (first half) 1. Welcome Paolo Tomasi was not able to attend because he is ill. James Campbell was not able to attend due to university obligations. 2. Reports and discussion 2.1 Chair (Wolfgang Schlueter) Since the last board meeting the following reports were prepared for publication: 1. for the APSG (Asian Pacific Space Geodynamics): "The International VLBI Service - two years after its implementation", by Schlueter, Vandenberg, Nothnagel, Whitney. 2. Summary Report: "Prospective Developments of the IVS over the next years". The report resulted from discussions during the 6th DB meeting and it was written on the basis of results of the WG2. 3. Report to FAGS: "2001 Activities of the International VLBI Service", by Schlueter and Vandenberg, was written as the required contribution of IVS to the FAGS Annual Report. A plaque and letter of appreciation were prepared for Tetsuro Kondo who left the board one year ago after serving for two years. The citation on the plaque reads: "In recognition of your significant contributions as representative of the Technology Development Centers in the IVS Directing Board from 1999 to 2001 the Board expresses its sincere thanks and appreciation." The plaque and letter were presented during the closing session of the meeting. 2.2 Coordinating Center Director (Nancy Vandenberg) Activities in 2001: supported two board meetings; published 2000 Annual Report and inaugural issue of the Newsletter; supported IVS web site and e-mail lists; coordinated the TOW meeting and the second General Meeting. Plans for 2002: two board meetings; 2001 Annual Report and two newsletters; elections for new board members; prepare for TOW2003. Y. Koyama recommended that the IVS Coordinating Center obtain virus protection software to ensure that files submitted to IVS do not propagate viruses. 2.3 Analysis Coordinator (Axel Nothnagel) Operations: We acquired a sixth Analysis Center to provide regular submissions: USNO. Now we have three solve and three Occam. There are problems with ACs changing their analysis setups because it affects the combinations. We are transitioning from C04 to TRF2000. Investigations: We are looking at the effects of network geometry on the solutions. For the second Pilot Project we received only seven series from three packages. This was disappointing. The IERS called for participation in the campaign to align EOPs with ITRF/CRF and there are only five inputs so far. The Analysis Coordinator will forward to IERS the solutions received from the Pilot Project. Organization: The SINEX extension for VLBI will be submitted to the IERS Analysis Coordinator after discussion and approval at the workshop. The PIVEX format has been extensively discussed during a visit by Anne-Marie Gontier to GSFC and is ready for discussion and approval. The IAU2000 resolutions for nutation/precession and the non-rotating origin will be discussed at a workshop this spring. Additional analysis discussion: H. Schuh proposed to set up tropospheric parameters as a new product for IVS. Comparisons with GPS are very good so IVS has a good competitive product. Results from both R1 and R4 sessions will be attempted each week. Data for the pilot project will be exchanged via the IVS Data Centers. A proposal will be sent to the board. The board decided to adopt the definition that a "Pilot Project" is a research and study project that is intended to lead ultimately to IVS products, as distinguished from a Working Group. The Pilot Project has a structure similar to the Working Groups that the board has established in the past, that is, the Pilot Project should propose to the board a charter, schedule, members, person to be the chair, and other relevant details. The board will discuss the proposal and decide whether or not to approve the Pilot Project. 2.4 Network Coordinator (Ed Himwich) Statistics of station performance show that the most significant problems in the past year are RFI, the Fairbanks antenna being down, Matera antenna problems, Hobart’s heads, and bad clocks. The data span examined is the year from Nov 00 through Oct 01, including 126 sessions and 757 station days. Data loss during the period is about 12%, corresponding roughly to an overall data loss of about 25%. Cellular phone transmissions due to IMT in Japan at 2135 to 2150 MHz are causing serious interference. This system may be worldwide soon. There are problems with the clock offset due to correlator adjustments. The clock offset behavior is not stable at the level required which is better than one microsecond. Further investigation will be need to understand why this is not the case. Solutions may be offered in the analysis area. Hayo Hase requested an antenna specification to provide advice to new antenna builders and for station upgrades. Receiver and DAS information should also be included. E. Himwich will coordinate the recommendations and make a proposal at the next board meeting. Additional network discussion Problem stations were discussed. Fortaleza has mechanical problems and it needs a Mk4 upgrade. Hobart has upgrade funds available but it needs new heads immediately. Svetloe will get an upgraded system on loan from NASA. A loan of a head assembly will be sought for Hobart. There are four formatters that may be available for loan to these two stations so that they can participate in Mk4 mode sessions. The board supports a plan to keep the network data quality as high as possible. W. Cannon reported that there are seven geodetic S2 DASs available: three in Canada, one for TIGO, one to loan to Kokee and one more available for loan to some station for the monthly EOP sessions (E3) in 2002. A. Nothnagel reported that there will be a pilot project of K4 intensive sessions using Tsukuba and Wettzell. Y. Koyama reported that CRL closed the Miura and Tateyama KSP stations. A letter should be sent to the IVS Chair withdrawing these two stations from IVS. One of the K4 systems from these stations is available. K. Kingham said that a letter to the Chair about the closing of Green Bank will be sent. 2.5 Technology Coordinator (Alan Whitney) The VSI-H specification version 6.2 is completed and this action is closed. An e-VLBI workshop will be held at Haystack in April 2002. The working group on future VLBI data transport is ongoing. At the end of February Mk5 systems will be deployed to Kokee and Wettzell, with two systems at the Haystack correlator. Data will be recorded in parallel on Mk5 and Mk4 systems during the daily intensives and the Mk5 discs returned to Haystack for processing. This will shake out routine operation. In June, 15 more systems will be available as a direct replacement of tape drives. Deployment of these systems to stations and correlators needs to be coordinated with IVS and the seven sponsors (NASA, USNO, KVN, JIVE, MPI, Noto, NRAO). The board expressed its strong support for development of e-VLBI. This was a key point in the WG2 report. Concern has been raised about the parallel development of disc-based systems in Europe at JIVE and at Metsahovi. Y. Koyama noted that CRL developed a PC board for sampling data, one board per channel. 3. WG1 report (Brian Corey) The purpose of the study was to lend VLBI’s expertise to the 15 ppb difference between VLBI and GPS TRF. This is thought to be due to the discrepancy in the phase centers of the GPS antennas. The WG1 studied the question of whether VLBI can do differential astrometry between quasars and GPS to determine the phase center of the satellite. The VLBA is an ideal instrument to use at L-band; eight stations are equipped with L-band front ends. Error sources are the reference source positions, ionosphere, troposphere, and instrumental effects. It may be possible to do the job but it will be difficult. Actually doing the measurements is beyond the scope of the working group. The draft final WG1 report will be circulated to the WG1 members, aiming for publication in the Annual Report. The work of WG1 is officially closed by the board. 4. WG2 report (Harald Schuh) Conclusions of the WG2 report are three areas for improvement, and the program for 2002-3 requiring 20-30% more resources. After this meeting, close WG2 and freeze the report. Y. Koyama suggested that the GM2 should pass a resolution related to the WG2 report so that there is a record of support for its conclusions. Wolfgang Schlueter said he is proud that IVS finished the report and that its authorship represents a wide array of IVS membership. 5. Program Committee (Nancy Vandenberg) The interim Program Committee has been meeting via telecon and e-mail since appointment at the previous board meeting. We discussed the role we should play in IVS: Membership should be representative of networks, operation centers, correlators, and analysis activities. Members should be appointed by the board (not elected), perhaps from a list of people willing to serve, for a flexible term. The purpose of the PC is to ensure that IVS goals are met and products provided through an appropriate observing program. The PC provides overall guidance to the Coordinating Center which is responsible for implementing the observing program through coordination with the IVS permanent components. The board decided to keep the membership as it is now. Alternates may attend the meetings so that the meetings have adequate representation for discussion. The PC could replace a member, subject to board approval. 6. IAU matters (Nicole Capitaine) The next IAU General Assembly is in Sydney in July 2003. There is time to make a proposal for a "joint discussion". N. Capitaine made a proposal for an "invited discourse" on how the services contribute to science. It would be appropriate for members of the IVS community to submit papers for commission 19 science meeting. The IAU 2000 resolutions will be discussed at an IERS workshop in Paris in April. 7. IAG structure and IGGOS (Wolfgang Schlueter) The IAG structure, terms of reference, and bylaws have changed and the new ones will take effect in 2003. The board voted to approve its participation as an IAG service in the new structure. IGGOS as a possible flagship of IAG ("reference frame precise and consistent for decades") will be based on the results of the Munich Symposia 1998. The IAG Services will play an important role in IGGOS. Invitations to the first meeting of the planning committee at AGU Spring Meeting will be sent out by Beutler. 8. FAGS (Wolfgang Schlueter) IVS received $3500 from FAGS which we intend to use for publication of a color brochure about IVS. 9. Meetings e-VLBI workshop: IVS and the GVWG are sponsoring a workshop to be held at Haystack Observatory in early April. The workshop will bring together astronomical and geodetic/astrometric users plus experts in wideband networks. OCCAM workshop: IVS is sponsoring a workshop to be held April 29-30 at TU Vienna for users of the OCCAM software. TOW 2003: The date of the next Technical Operations Workshop will be in May 2003. General Meeting 2004: The Canadian agencies are considering hosting the next General Meeting in Ottawa. (Further discussions during the meeting at Tsukuba were held and a final decision was made to host the meeting. The announcement was made to participants during the closing session.)