11th IVS Directing Board meeting Summary notes by NRV 040311 Ottawa, Canada (Lord Elgin Hotel) February 8, 2004 Attending: Wolfgang Schlueter, Kerry Kingham, Zinovy Malkin, Arthur Niell, Alan Whitney, Chopo Ma, Axel Nothnagel, Shigeru Matsuzaka, Bill Petrachenko, Yasuhiro Koyama, Franco Mantovani, Harald Schuh, Ed Himwich, Patrick Wallace, Nancy Vandenberg 1. Welcome (Wolfgang Schlueter) The Descartes Prize awarded in November 2003 was a very important event for VLBI. Congratulations to the working group "Non-rigid Earth Nutation Theory" led by Veronique Dehant. Two board members, Harald Schuh and Chopo Ma, are members of the group. The prize gives good public information, and shows that IVS/VLBI contributes strongly with the EOP time series. 2.a. Chair's report (Wolfgang Schlueter) A letter was sent to the rector of the Universdad Concepcion requesting that they host the next General Meeting in 2006; they responded in agreement. An announcement will be made at the end of the General Meeting. There is a plan to establish EP-IGGOS (European Partners in IGGOS). All IAG services and related European groups should become the members of EP-IGGOS (instead of having individual agencies or countries as members). In Europe the astronomers are organized as the EVN, and a comparable group in geodetic VLBI is needed and will be constituted similarly to EUROLAS (lasers) or EUREF (GPS). Considering the advantage of being locally close together in Europe, a meeting was held with the ILRS chair (Werner Gurtner at Berne) and IGS chair (John Dow at Darmstadt). These three services have similar structure, including internationally operated networks, and are faced with similar problems. The exchange of information and experiences turned out to be very useful. The responsibility of the services with respect to the support of contributing agencies was discussed. A document will be written that explains the importance of the products of the services and the need of the contributions by the agencies. The IAG services should jointly increase their visibility. IGS has a booth that they set up at meetings. They have agreed in principle that IVS and ILRS could join the booth as a way of pointing out our collaboration and of distributing some of our documents. The three services each have station information files (called log files or configuration files) which contain comparable information. It would be useful to ensure that the contents of all files are harmonized, for example if the height of the met sensor relative to each system is included. It will help to avoid misinterpretations if all use similar philosophies for the information. 2.b. Coordinating Center report (Nancy Vandenberg) A new data flow diagram for IVS was prepared. The next publication will be the Annual Report 2003, followed by the General Meeting Proceedings. Newsletters are published in April, August, and December and contributions are always welcome. The web site is being redesigned by working with a professional web designer at Goddard. The observing program for 2004 is nearly the same as for 2002 and 2003, because no new antenna observing time is available. The totals are about 175 session days (3.5 days per week) and 1100 station days. Total data to be recorded this year is about 1000 TB (1 peta-byte). Usage of Mark 5 is increasing gradually. When the large number of modules at USNO is ready to ship next month, most stations can become full-time Mark 5. By the end of the summer it appears that most stations will be Mark 5 or K5. Monthly telecons are held with ILRS and IGS central bureau staff, to keep in touch about common problems. The three services were awarded the INDIGO proposal but no funding has been received yet. 2.c. Analysis Coordinator report (Axel Nothnagel) There are 6 Analysis Centers that contribute to the EOP combination product. Comparison of the rapid combined product to IGS shows wrms for X, Y are 63, 53 micro-arcsec. Comparison of the quarterly solution shows about 100 micro- arcsec. Comparison to C04 is worse, but not understood. The IERS combination pilot project requests a contribution from each service only, not from individual Analysis Centers. The concept is that the "weekly" SINEX files will be combined by IVS, sent to the IERS combination centers, and then IERS will combine these to get a fully consistent set of ITRF/EOP/ICRF. Chopo Ma suggested we submit one SINEX solution (not a combination) to IERS to get started. Later we can submit a combined solution. 2.d. Network Coordinator report (Ed Himwich) The station performance analysis for 2003 covers 188 sessions and 1040 session days. The loss was 14.2%, compared to 12.2% in 2002. Is this a trend to worse performance or a one-time problem year? Major subsystems contributing to the data loss: 25% receiver problems, 18% antenna problems. Major issues were the Matera rail, Simeiz recorder, and TIGO upper X-band channel problems. How to solve maintenance problems with limited resources is still an issue. Clock offsets still need a unified approach, but procedures at the stations seem to change from time to time making unification problematic. Koyama-san showed information about a 32-m communications antenna in Peru that is being converted to scientific use. NAOJ will support the station with a maser and a K5 system. The geographical location is very good. 2.e. Technology Coordinator report (Alan Whitney) The VSI-E draft is being reviewed by the committee. The protocol is based on RTP, making many pre-existing tools and utilities available for use. David Lapsley at Haystack has implemented an experimental version. Strong cooperation with the networking community is ongoing. There are now about 75 Mark 5 systems and 500 disk packs deployed; 85 systems are expected by the end of 2004. Mark 5B will use the same chassis, have VSI interface, and station unit capabilities. Correlators will be upgraded after the stations upgrade. The compatibility path is that the Mark 5B can read only 5B disks, the Mark 5A can read both. A transition plan will be needed to make the changeover smooth. So far 4 24-hour sessions have been recorded at Kashima and transferred via e-VLBI to Haystack, where the data is recorded on Mark 5 disk packs and shipped to the appropriate correlator. 2.f. WG3 report (Alan Whitney, Arthur Niell) The VLBI2010 Working Group has a session in the General meeting and a group meeting on Friday. There should be a draft report completed by April, final report by July. 2.g. Pilot Project: baselines (Axel Nothnagel) Proposals were received in October from 3 Analysis Centers (IAA, GSFC, BKG) to provide SINEX files now, 3 to provide files at a later date (DGFI, IGG, ASI). The level of repeatability is about 3 cm on the Algonquin-Fortaleza baseline. There are systematic differences up to 8 mm between GSFC and BKG solutions, and also differences with IAA/Occam solutions that have to be looked into. A web page is being set up to access the test products. 3. Various technical reports. 3.a. Vienna mapping function (Harald Schuh) IGG is providing mapping function parameters on an operational basis. They calculate IMF and VMF, have a 5 day delay, and provide 6-hour time intervals. A password is required to access the results because the ECMWF requires that their data be used for scientific applications only. Also, IGG wants to know its users and be able to track down problems. The VMF provides improvements over NMF. 3.b. Vienna student project (Harald Schuh) The goal of the project was to have students do the entire process of scheduling, correlating, and analysis. A webcam was set up at TIGO and Hayo explained the observing. Some students went to Wettzell to observe. One baseline was correlated so far. 3.c. e-VLBI activities at CRL (Yasuhiro Koyama) CRL will become NICT (National Institute of Information and Communications Technology) as of April 1. The K5 system at Kashima was used for CRF and T2 sessions. Data was transferred to Haystack and recorded on a Mark 5 disk module. A timing offset of about 1.5 microsec was found between the tape and disk recordings, which is being investigated. The network connection at Kashima will be upgraded to 1 Gb/s in April. The K5 will start to be used at Tsukuba when they have a better network connection; meanwhile the K5 disks can be recorded at Tsukuba and shipped to Kashima for data transfer. There will be no need to convert K5 to Mark 5 format if the VSI-E interface is used. 3.d. Met sensor calibration (Arthur Niell) Bob Philips was supervising getting the met sensor calibration data, and he got 15 responses. Bob is leaving Haystack, so another person has to be found to do this job. Arthur and Harald will continue the coordination. 3.e. S2 situation (Bill Petrachenko) Wayne Cannon's lab is operating at a very low level and the Canadian Space Agency funding is now gone. Maintenance for the S2 DAS and software is located at GSD now. The S2 DAS for Svetloe is ready to be shipped on Wednesday. The record and playback terminals are aging. They have been maintained using spares from VSOP but with Svetloe in the E3 network the correlator needs 6 stations and only has 5. One set will be borrowed from Wayne. Upgrading the correlator to Mark 5 is being considered, though conversion software will be needed. There is still a 3-month backlog at the correlator due to there being only one operator (Bill). The CTVA will remain at St. John's one more year, possibly longer. 3.f. Digital BBCs (Franco Mantovani) Gino Tuccari leads an EVN group to develop digital BBCs, with participation from CNR, MPI, JIVE, and Jodrell Bank. With the Mark 5B there will be no need for the formatter and the BBCs are becoming obsolete. A project plan was requested from Gino. 3.g. Mark 5 correlator experience (Kerry Kingham) The Mark 5 development happened very fast: from prototype in March 2001 to deployment in spring 2003. The gains from Mark 5 are: increased efficiency with processing factors decreasing to about 1.5 times record time, demonstrated unattended correlation, interoperability between K5 and Mark 5, and less operator intervention needed. Issues that remain are: operator training, a complex and fragile system (including Linux administration, manual reboots, StreamStor problems), station unit synchronization problems, and an unknown disk failure rate. (Alan said that 1 out of 200 disks have failed.) Overall the phase-in logistics for Mark 5 are similar to the experience for thick to thin tape. Shipping problems have been minimal and no customs problems have arisen (yet). Overall the transition to Mark 5 has gone very smoothly and is already having a positive effect on the IVS observing program. 4. Items related to IAG, IAU, EVN 4.a. IAG Commission 1 (Chopo Ma) Hermann Drewes is president of IAG Commission 1. The services have three representatives recently elected: Chopo Ma (IVS/IERS), Werner Gurtner (ILRS) and John Ries (IGS). A very elaborate structure has been set up, though there is no activity yet. It remains to be determined how the commission and services will interact. 4.b. IERS Matera workshop (Chopo Ma) There were active discussions in 5 sessions at the Matera workshop. The workshop recommendations are: local ties should be at the 1 mm level, local surveys have high priority, VLBI sites with GPS should in the main IGS analysis, IERS will maintain a local information data base. Standards were proposed for surveys, analysis, and documentation. 4.c. IERS Working Groups (Chopo Ma) There are three working groups that are most important with respect to IVS. (1) WG1 Datum Definition of Global TRF: The charter not set up yet. Geoff Blewitt is chair. The purpose is to set conditions on the conceptual basis of the reference frame. (2) WG2 Site Survey and Co-location: The charter was distributed, and the IERS board is voting on it. The chair is John Dawson alternating with Perguido Sarti. (3) WG3: Combination has Markus Rothacher as chair. 4.d. IAU (Patrick Wallace) Jan Vondrak was elected Division 1 Fundamental Astronomy vice-president (and next president). The summer AAS meeting in Denver will have a special session on the IAU resolutions. There are 2 new working groups: 1) Precession and the ecliptic, chaired by James Hilton, and 2) Nomenclature, chaired by Nicole Capitaine. If the right words can be selected it may help the new system to be more accepted. 4.e. FAGS (Nancy Vandenberg) There were no funds distributed by FAGS for 2003. Next year any funds will be distributed directly by ICSU. FAGS is participating in the IPY (International Polar Year) in 2007 and requested the services to provide any inputs. 4.f EVN status (Franco Mantovani) The EVN consortium is 14 institutions operating 16 telescopes. The MOU of 1985 was renewed in 2002. The EVN plans to be Mark 5-only in 2004; the main problem is purchase of modules. JIVE will process the "global" sessions (that include VLBA stations recording on tape only). RadioNet received funds from the EC for 5 years to fund users of the EVN and to run the EVN itself. 4.g. VLBI video (Harald Schuh) Harald was asked by a journalist for some video about VLBI, following the Descartes prize, but none exists. Veronique has one but it's not very good. Nancy said that after the color brochure is completed, we can work on developing a video using the multimedia lab services at Goddard. Wolfgang noted that Bavarian TV made a 30-sec video. 5. Meetings. Upcoming: - TOG will be held at Wettzell, April 1-2 - 3rd e-VLBI meeting will be in Japan, October 6-7 - 7th EVN symposium is in Toledo, Spain, October 12-15 - Journees in Paris, September 20-22 - next IVS board meeting in Kashima, October 8 - next EVN board meeting at Onsala in spring