Summary Notes from the Sixth IVS Directing Board meeting Spanish Research Council, September 9, 2001, 0900-1730 First version Oct 2, 2001 Updated Oct 5, 2001 (added descriptions of Working Groups) Attending: K. Kingham, A. Whitney, J. Campbell, A. Nothnagel, H. Schuh, Y. Koyama, N. Capitaine, S. Matsuzaka, E. Himwich, A. Niell, C. Ma, N. Vandenberg, W. Schlueter, P. Tomasi W. Cannon was not able to attend due to teaching obligations at the start of term. 1. Welcome Wolfgang Schlueter welcomed Wayne Cannon, in absentia, back to the board as the newly elected third At Large member, based on modifications approved to the Terms of Reference at the fifth board meeting. 2. Reports and Discussion Chair's report (Wolfgang Schlueter) The application of IVS to become a member of FAGS was approved at the March meeting of the FAGS Couneil. The FAGS home page has information about IVS now (www.kms.dk/fags). The Analysis Center supported by AUSLIG is a new IVS component. IVS received an award from the Japanese Ministry of Public Management, Home Affairs, Posts, and Telecommunications for development of the VSI standard. A report about IVS was submitted to IAG and published in the Traveaux, released at the IAG meeting in Budapest earlier this week. At the CSTG Executive Committee meeting in Budapest there was some discussion about the ISGN (International Space Geodetic Network) sub-committee that had been headed by John Bosworth. ISGN activity will continue at a lower level, mainly for ties work in coordination with Zuheir Altamimi. Bulletin 17 of the CSTG should be released soon. Axel Nothnagel has submitted a contribution about combination of results for the IVS official product. Other reports should be the WG1 report on the GPS phase centers and the WG2 report on products and observing programs. The new IAG structure was discussed extensively at the IAG meeting. All of the current sections will be merged into four commissions: geometric reference frames, gravity, earth rotation, and positioning and applications. Commissions can form subcommissions and working groups. The eight services are on the same level as the commissions. Coordinating Center report (Nancy Vandenberg) Master schedule: the 2001 schedule has been kept up to date, and a new Station Usage chart was added to the web site. Master files for 1979-2001 were completed and links to all the files were put onto a web page. As decided at the Analysis Workshop, DOMES numbers and CDP numbers were added to the station codes control file. Publications: The Annual Report for 2000 was published in late May. The IVS brochure was printed in July and copies distributed to all board members. Copies are available upon request from anyone. Other: The first IVS annual report to IERS was prepared. Analysis Coordinator report (Axel Nothnagel) The final report of the first Pilot Project was completed. The call for the second Pilot Project was sent; files are due in mid November. We are investigating discrepancies between IVS series and the IERS C04 standard series. The IVS combined series is now used as an external check for Bulletin B. We now have a fifth Analysis Center, AUSLIG, contributing to the combination. Combination procedures are well documented. The strategy of the combined series is to not change the series, rather it is frozen and new points are added to it. When new models come into use we will have separate series. One activity that takes quite some time is responding to questions about VLBI analysis, how to do it, giving advice etc. This position is very visible. A problem with nutation angles has appeared: whether to use totals or offsets. After discussion, the board recommended the continued use of offsets from the 1980 model until 2003 when the new IAU model will be in effect. In SINEX files totals must be used. The PIVEX (Platform Independent VLBI EXchange) format activity is being led by Martine Feissel. A new format is being worked out for the data base file that is currently the output of the VLBI correlators. Network Coordinator report (Ed Himwich) Station upgrades: The EVN plans to loan a spare Mk4 formatter to Simeiz so that it can participate in sessions recorded in Mk4 formats. Wettzell agreed to loan its spare to MPI as a member of the EVN if a failure occurs while the EVN formatter is at Simeiz. Recording at Simeiz in this mode can only be done on 14 tracks until the recorder is also upgraded. The Svetloe station will receive a Mk3 system on loan from NASA, and the Russians will pay to have it upgraded to Mk4. Clock offsets: There is a need to calibrate station clocks to a level better than the desired UT1 accuracy specified in the WG2 report. One question is whether the calibration should be applied at the correlators or at the analysis centers. There are pros and cons to each method. TOW2001: The 2001 TOW was held at Haystack in March. It was even more successful than previous TOW meetings because there was more time for discussion, and even more discussion time was requested for the next TOW. Site visits: Visits to IVS sites are done to demonstrate IVS interest and concern for station performance. Onsala was visited in June after the TOG meeting, Kokee was visited in July. Station problems: Fortaleza has a problem with worn gears and more funding will be needed to fix it. We still need site configuration files from 10 stations. Web page: A Network Coordinator's web page was set up. It now has various documents, and the station problem plots will be put there. Station performance information is still being accumulated in the performance data base. In summary, most data losses were due to S-band RFI and to Gilmore Creek losing a dewar. Data loss is still at the ~10% level. Technology Coordinator report (Alan Whitney) The VSI-S standard is in the fifth draft and is more than 20 pages long. It is expected to be complete in the next 6 to 12 months. A Mark 5 system is currently under development. Approximately 12 systems will be deployed by spring 2002. The Mk5A is a replacement for the tape drive, to be available in spring. The Mk5B is fully VSI compatible and will be available by fall 2003. 3. Working Group 1 Brian Corey, WG1 Chairman, send a brief status report to the meeting. The charter of WG1 was to investigate whether VLBI could be used to measure the phase centers of GPS satellites to sufficient accuracy to make the measurement worthwhile. Previous reports from WG1 indicated that VLBI measurements could not be done with the required accuracy. Brian recommended proceeding as follows: 1) get a consensus of the Working Group members that a report should be prepared and agree on its conclusions, 2) complete the report and distribute it. 4. GM Tsukuba Yasuhiro Koyama presented plans for the second General Meeting, to be held in February 2002 at Tsukuba, Japan. The LOC may have some travel funds to support attendance at the meeting. The initial Program Committee met following the board meeting. 5. Working Group 2 Working Group 2 was appointed at the previous board meeting. Its purpose was to study IVS products and recommend observing programs. Harald Schuh presented a summary of the Working Group's report, including results of the Working Group meeting from the previous day. The first step was to describe the present status and assign a rating to current results based on reliability and redundancy. The next step was to establish some goals for the next few years of IVS and suggest future products. Finally future observing programs to fulfill the goals would be developed. In the report, Table 1 covers the first two steps and the report text describes present results and the goals. Section 4 concentrates on users of the IVS products, and section 6 recommends observing programs. It was decided that the report would be finalized within the next few weeks, reviewed by the board, and released for publication after approval. An interim Program Committee was set up consisting of a subset of members of the Working Group. This committee will support the Coordinating Center during planning of the 2002 observing program. 6. FAGS financial support Nicole Capitaine asked for a discussion about the use of the money to be given annually to IVS by FAGS in the amount of $3500. Wolfgang Schlueter suggested it could be used for travel support, publications, and marketing. Nancy Vandenberg suggested updating the VLBI brochure, first printed several years ago, and using the money to print it in full color. The board supported this idea, and noted that the brochure would have to be focussed more on international programs. 7. Publications Kerry Kingham noted that we need to promote IVS, via publications and other means. Wolfgang Schlueter said that a newsletter would give information and visibility for IVS. Nancy Vandenberg requested help with the publication; Heidi Johnson (Haystack) and Hayo Hase (BKG) wil assist. 8. Meetings IERS convention workshop: Nicole Capitaine reported that there will be a workshop on the IERS convention updates in Paris, near the date of the EGS in spring. European meetings: It was suggested that the European meetings be changed so that they are held every two years instead of every 18 months, and that they alternate with the IVS General Meeting. The European meetings should be announced more widely.