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Fifth General Assembly of the International Laser Ranging Service (ILRS)
Matera, Italy
Thursday, November 16, 2000
Editor's Note: All Attachments are available in hard-copy. Please contact Dr. Michael Pearlman (email Pearlman@cfa.harvard.edu), ILRS Central Bureau Secretary, if you would like a copy of an attachment. The minutes are also available in MS word.
The Fifth General Assembly of the International Laser Ranging Service (ILRS) was held in Matera, Italy on November 16, 2000, in conjunction with the Twelfth International Workshop on Laser Ranging. The agenda for the General Assembly is included in Attachments 1.
Governing Board
The Governing Board (GB) Chair, John Degnan, welcomed the participants and reviewed some of the key developments over the past year (see Attachment 2). The Central Bureau conducted elections for the Governing Board members for this next two-year term. In the new Board, Graham Appleby replaces Richard Eanes as one of the two Analysis Center Representatives and Georg Kirchner replaces Francois Barlier as one of the At-large Representatives. Congratulations to Georg and Graham and we extend our appreciation to Richard and Francois for their participation.
At the ILRS Governing Board meeting held on November 15, John Degnan was reelected Chair of the Governing Board for a second two-year term Working Group Chairs and Co-Chairs were also appointed (see Attachment 3).
The First ILRS Annual Report is now on-line and is in printing to be distributed by years end. Several preprint copies were handed out to members of the Governing Board. Instructions for the next Annual Report will be distributed shortly. Whereas the first Annual Report contained significant background and detail, subsequent annual reports will be viewed as opportunities to update information in a concise manner.
Degnan reported on the recent reorganization of the IERS. Each of the measurement techniques will now have two representatives on the IERS Board. The ILRS Governing Board appointed Ron Noomen and Peter Shelus as the SLR representatives.
Central Bureau
Mike Pearlman introduced the members of the Central Bureau.
Van Husson reviewed the Network Performance (see Attachment 3). About half of the stations are making the 1500 pass per year satellite pass quota. Many stations showed a significant increase in data yield over the past year. Most notable were the improvements at San Fernando, Beijing, Shanghai, Simosato, and Riga. Most of the stations met the 2-cm long-term bias stability criteria, but some of the stations need some careful attention. Most of the stations had 90% or more of their normal point data accepted; a few stations were below the 75% mark indicating that they need to improve operational procedures and on-site data examination.
Van Husson reported on ILRS website enhancements over the past year (see Attachment 4). The issuance of the ILRS Quick Reference Card, the on-line web site map, and improved site organization has helped users navigate more easily through the website. Expanded Station and Data Product pages provide considerably more information. All ILRS reports have been consolidated under SLReports. Urgent mail has been added for rapid announcements to the stations. Up-to-date system status is on-line for most of the stations. Additional interactive queries and email exploders have also been added.
Van Husson has been working with the stations to complete their site logs (see Attachment 5). As of the beginning of November, site logs from thirty-four of the stations were accepted and posted on the web. Van continues to work with the remaining stations to help them toward completion. Several suggestions have been made for the inclusion of additional station information in future iterations of the form. Van plans to add a search capability and hyperlinks to improve user facility. (One option may be to place all of the information into a master spreadsheet.) The Networks and Engineering Working Group intends to set up a "group of subject experts" to review the Site Logs for consistency. An up-to-date Site Log is a requirement for all ILRS stations.
Mike Pearlman reviewed the status of campaigns and priorities (see Attachment 6). Three campaigns had been approved to run through 31 October 2000. The campaigns were extended for an additional month to coincide with the months delay in the scheduling of the ILRS General Assembly (and the Laser Ranging Workshop). M.K. Cheng from the University of Texas requested the Beacon-C Campaign for spatial and temporal gravity field studies. A request to extend this campaign through 31 December 2001 is being submitted.
Tracking on SUNSAT has been suspended while the satellite is being stowed in an inverted position for thermal recovery. SLR continues on the GFO-1 Satellite as the only means of precision orbit determination for the on board altimeter. A request for operational tracking support is anticipated.
Priorities continue as assigned at the Fourth General Assembly in Nice, with the additional of the Champ satellite as first priority.
Pearlman also reviewed the progress made on some of "our challenges" identified at the last General Assembly in Nice. Major improvements have been made in the tracking of low orbiting satellites with the implementation of rapid (hourly) data submissions and daily (and if necessary subdaily) renewal of predictions. This has been demonstrated very successfully with the low orbiting CHAMP satellite launched in July. Data production from the stations continues to increase and the Analysis Community has made significant progress in comparing results from different groups and resolving differences in results. The SINEX format has been adopted for the SLR results and seven SLR solutions are being included in the ITRF 2000 reference system. Development continues on the ILRS web site and considerable progress has been made with the implementation of the Site Logs and the standardizing of procedures.
Scott Wetzel reported on the operational improvements that have been implemented over the last six months (see Attachment 7). A backup-normal-point delivery system now provides alternative data delivery paths in case either EDC or HTSI are not in operation. A test of the system is scheduled for early December when EDC is scheduled to be down for renovations. Sub-daily normal point delivery (with provisions to support hourly turnaround) has been implemented; on average stations are delivering data several times a day with some as high as 8-10 times a day. From many stations, data is only 1 3 hours old when it reaches the Data Centers. The rapid data delivery has made it possible to accelerate the refreshing of predictions. In the case of CHAMP, new predictions were issued as often as twice per day, helping greatly to overcome deterioration of predictions. A prediction exploder has been established at the CDDIS to expedite distribution of new orbital elements. A new on-line file with a record of all received passes is available for stations to readily and rapidly confirm data delivery. A facility for rapid decimation of urgent messages to the stations has been set up. On-line station status reporting continues to give the users an up-to-date view of the network operations.
Marc Torrence gave the Science Coordination Report. Work continues on expanding the on-line bibliography and the providing scientific reference material for users (see Attachment 8).
Subnetwork Reports>
EUROLAS
Werner Gurtner reported on the EUROLAS activities (see Attachment 9.) TIGO is being prepared for deployment to Conception, Chile in mid-2001. The MLRO is presently on site at Matera undergoing acceptance tests prior to full operations; some overlap in operations is being planned between the MLRO and SAO-1 prior to SAO-1 closeout. It was pointed out that SAO-1 has been in operation for 30 years, first in Natal, Brazil and then in Matera. Envisat is being prepared for launch in 2001.
NERC data analysis, which examines overlapping passes in Europe, continues to provide a powerful diagnostic on station performance. Attempts are being made to use it elsewhere. Real-time data and status exchange has helped stations keep close track of satellites in particularly low, drag perturbed orbits. EUROLAS is also working with other space techniques to support GLONASS.
WPLTN
Hiroo Kunimori reviewed the activities of the WPLTN (see Attachment 10). The stations at Yarragadee and Mt. Stromlo continue to perform at very impressive levels. Other stations such as Changchun, Tateyama, Koganei, Kashima, Kunming, Shanghai, Simosato, and Beijing all showed improved performance. The data yield from WPLTN is improving and has greatly strengthened coverage in the Western Pacific region. A number of other stations in the region are not performing well and need some attention. Two of the Keystone stations, Tateyama and Koganei, have been reopened to support urgent crustal motion studies on the Tokyo region. Mobile stations operations by JHD continue to position some of the offshore islands. NASDA is also embarking on the construction of a new high power SLR system for Tanegashima.
In 1996 the National Space Development Agency of JAPAN (NASDA) initiated "GUTS", a program for global and high accuracy trajectory determination. The objective of GUTS is to perform precise orbit determination using GPS as the main instrument and SLR as a calibrator to deliver precise orbital ephemeris for Earth observation mission users. The near-term mission targets for GUTS are ADEOS-II in 2002 and ALOS in 2003. The required position accuracy for the ALOS mission is 25 cm. The ground segment of GUTS consists of GPS and SLR stations for the observations, and a master control and operation planning subsystem. NASDA will construct a fixed SLR station at Tanegashima, a southern island in Japan near the launching facility. The GUTS SLR system would like to cooperate with the CRL and JHD SLR systems, as well as with the ILRS network to fulfill mutual objectives. In 2000, NASDA completed one GPS ground station and the precise orbit determination subsystem. The preliminary design phase for SLR system is underway.
In China, a GPS CORE network has been established and the VLBI and fixed and mobile SLR systems are contributing to the national crustal motion measurement activities.
A campaign of high power SLR stations is being organized to provide continuous tracking on ETS-VIII. Candidate stations are CRL, Mt Stromlo, Mt Haleakala, and NASDA (Tanegashima).
NASA
David Carter reported that MOBLAS-6 is now operating in Hartebeesthoek, South Africa (see Attachment 11). A delegation is on its way to South Africa to attend a dedication next week. Discussions are still underway with the University of La Plata for the relocation of TLRS-4 to Argentina. Upgrade work on the Mt Haleakala system has dragged on intolerably because of delays with the control system contractor. Meanwhile the system provides a very small quantity of data. Discussions are underway with CNES on options to better stabilize the team at the Tahiti site. Data has been forthcoming, but yield and quality are suffering because of the personnel situation.
Work continues on the SLR2000. The prototype is scheduled to begin field testing in the second half of 2001.
Data Centers
EDC
Wolfgang Seemueller (see Attachment 12) reviewed the status of the EDC. He explained process and protocol associated with moving the data through the system on an hourly basis, issuing daily and subdaily predictions, and implementing backup data delivery and prediction distribution procedures. He also pointed out that the new use of SLReports has considerably reduced the traffic on SLRmail. Seemueller also highlighted several areas such as differences in directory structure that still need resolution between EDC and CDDIS.
CDDIS
Maury Dube reported on the status of the CDDIS (see Attachment 13), including its implementation of the new procedures discussed above. Increased levels of security are being enforced at GSFC and as a result Telnet is being disabled. Secure shell is being required for interactive access, and secure copy protocol will soon be required for deposit of data. Efforts are underway to resolve some small discrepancies in the data holdings of CDDIS and EDC.
Working Groups
Missions
Hiroo Kunimori reported on the activities of the Missions Working Group (see Attachment 14). The Beacon-C, GFO-1, and Sunsat campaigns were extended through November 30 to accommodate the schedule slip in the Laser Workshop and hence the ILRS General Assembly meeting. Requests for continuation are anticipated for both Beacon-C and GFO-1. Sunsat is inverted at the moment, precluding ranging. We await word on their long-range plan. It is expected that the US Navy will accept the GFO-1 satellite early in 2001, now that the SLR has demonstrated its ability to rescue the mission, after the failure of the GPS system.
Thirteen new missions requiring SLR are scheduled for launch over the next three years. ILRS tracking request forms are still required from most of them. We continue to have discrepancies in satellite identification numbers and codes. The COSPAR identification number on CHAMP has been settled (0003902). Some discrepancies continue with the new GLONASS satellites.
The Missions Working Group web page has been established in the ILRS web site with general satellite information and ranging information. The Working Group is collecting additional information on the current and future satellites to support the satellite signature studies. The Working Group needs to implement (perhaps with the Central Bureau) a procedure to routinely verify user needs on each SLR satellite and to fuse these needs into the satellite priorities for the network. The process of completing and submitting Tracking Request Forms needs to be facilitated, and we need to be more earnest in the development of the Missions Support Plans.
Networks and Engineering
Werner Gurtner reviewed the activities of the Networks and Engineering Working Group (Attachment 15). The Working Group originated and helped establish "Urgent" mail, the backup data submission procedures, and a number of other email exploders for rapid dissemination of information. The draft report from the Florence workshop on SLR Calibrations has been circulated for review. The satellite link budget for many of the SLR satellites is now accessible through the ILRS web site; the remaining satellites will be added. A small study group has been organized to develop a set of qualifications for ILRS entities (in particular the stations) to be used to evaluate current ILRS participants and to be used as a standard for new entries. The Working Group also sees the need to develop a set of tracking characteristics for the satellites as a guide for the stations.
Data Formats and Procedures
John Luck reported on the activities of the Data Formats and Procedures Working Group (see Attachment 16). In many cases the activities of this Working Group are closely linked with those of the Networks and Engineering Working Group. Rather than drawing very firm boundaries on the responsibilities of these groups at the moment, it was agreed that we should let them work together where appropriate to provide the most benefit to the ILTS activities. The Central Bureau has implemented many of the concepts recommended by these Working Groups. Hourly data flow procedures are in place, and data transmission procedures have been documented. An ftp file with the current status of data submissions (one line per pass) has been established at CDDIS. Periodic comparisons of data on file at CDDIS and EDC are underway to ensure that data is not being lost at either data center. After a long process, we are near closure on the format for the maneuver message. Daily and subdaily (when appropriate) predictions have been established along with a new prediction exploder. The need for a common normal point tree structure is still under study. The site logs have been instituted; we should now be able to close out the configuration files. Urgent mail and other new mail exploders have been implemented; a notification to the community is required. Station status reporting has been established, and some normal point format and integrity checks have been implemented to help speed up data flow.
The Refraction Study Group, headed by Stefan Reipl, was formed earlier this year at the meeting in Nice. Reipl reported on their progress to date (see Attachment 17). The Study Group was tasked to (1) assess the adequacy of the Marini and Murray model to meet 1 mm accuracy requirements down to 15 degree elevations, (2) define new models and procedures to provide the necessary improvements, (3) define the data needs to evaluate the models, and (4) make an overall recommendation to the ILRS on how to proceed. The Study Group found that based on ray tracing comparisons, the Marini and Murray model shows significant errors (several cm) at 15 degrees, and that Gardner mapping functions modified with a new dispersion model showed considerably better results. The group intends to use some two-color data for verification and to examine the effects of horizontal refraction gradients. Results from their studies are accessible at:
A proposal for a new LLR Prediction Format, capable of extension to lunar and deep space transponder missions is under development. At the Data Formats and Procedures Working Group Meeting on Thursday evening (after the General Assembly), a new Study
Group, chaired by Randy Ricklefs, was formed to oversee this task.
Analysis
Ron Noomen reviewed the progress of the Analysis Working Group (see Attachment 18). Noomen outlined the new organization of the IERS. Bernd Richter is the head of the new IERS Central Bureau. Markus Rothacher is the new designated Analysis Coordinator, and each of the services now has two representatives on the Directing Board. Noomen pointed out that seven SLR solutions are being included in the ITRF2000 development process, and that SLR was being relied upon for scale and origin. (This is quite a pleasant change from earlier ITRF versions that claimed very little reliance on SLR).
The Working Group continues with its pilot projects on positioning and Earth orientation to improve consistency among the products of the different analysis groups with the intent of creating an official ILRS product. At workshops held in Florence, Frankfurt, Delft, and Matera during the past year, solutions using 30 day prescribed sets of LAGEOS I and II data were compared and scrutinized for inconsistencies. The SINEX format was fully adopted and a number format, modeling, and initial condition issues were resolved. In the next iteration, due February 1, the Analysis Groups will provide Lageos 1, Lageos II, and Lageos I/II combined solutions with station positions and 1-day time series of EOP for the period. Twelve centers are participating in the Pilot Projects. Several of the Centers are also comparing and combining the solutions for review, in preparation for the next Analysis Workshop scheduled for March 22-23 in Nice. The Pilot Projects will also tasks to compare orbits, benchmark orbital software and processing procedures, and harmonizing the QC processing for the network stations.
Signal Processing
Graham Appleby presented a summary of the activities in the Ad-Hoc Signal Processing Working Group (See Attachment 19). Work continues on the modeling of the GLONASS and ETALON satellites and determining an accurate response function. A table of center-of-mass corrections for spherical satellites under low return energy conditions has been developed. C-Spad extrapolations to higher levels of energy are underway. Additional information has been added to the Site Logs to provide more detail on operational practices that could influence the center-of-mass correction. Models need to be developed for the MCP. Procedures to provide better information on array characteristics for both current satellites and new missions should be instituted, and adequate algorithms, once developed, should be made readily accessible on the web site.
Campaigns and Mission Support
ERS-1/2
Roland Schmidt presented a report on the ERS-1 and 2 (see Attachment 20). ERS-1 was well supported by SLR, with an average of 77 passes per week through to its demise in March 2000. ERS-2 continues to work well. The radio tracking system coverage with PRARE, is deteriorating with only 8 stations now operating. The SLR network is averaging about 83 passes per week from an average of 12 sites. The SLR data is being used for predictions, operational POD, and gravity field research. The SAR and the radio altimeter data are being used for Earth surface, ocean, and ice mass monitoring and gravity field modeling.
CHAMP
Roland Schmidt also reported on the CHAMP activity (see Attachment 21). SLR began tracking CHAMP early in the mission and is now providing an average of about 40 passes per week. The accelerated data delivery (as rapidly as once per hour for some stations) has facilitated daily and twice daily refreshing of the predictions. The combination of GPS and the rapidly available SLR have been crucial in providing good quality orbits for this low orbiting satellite. The CHAMP Mission is now in the midst of its calibration/validation mode for the microwave tracking experiments. SLR plays an important role in the computation and evaluation of the scientific applications of the mission.
TOPEX/Poseidon
Mark Torrence gave an account of the TOPEX/Poseidon activities (see Attachment 22). The mission has operated well and has been a great success since its launch in August 1992. The SLR network is providing about 160 passes per week. The data quantity continues to increase. The SLR-DORIS combination is supporting orbital accuracies of 2-3 cm with continued improvements anticipated. The SLR is helping to keep the reference frame stable and has been crucial in the modeling of the gravity field and the other satellite force models.
GFO-1
Mark Davis reviewed the status of GFO-1 (see Attachment 23). The US Navy launched GFO-1 in its program to develop an operational altimeter system for measuring and predicting mesoscale variability and basin-scale oceanography. Since the early failure of the radio tracking system, the mission is relying solely on SLR, which is providing orbits with radial accuracies of 5-6 cm. The on-board radiometer and altimeter are working as expected and compare well with TOPEX and ERS-2 measurements. Range noise is about 2 cm and bias is down to a few cm compared to TOPEX and ERS-2. Sea state is being determined to a few percent and ionospheric corrections are being estimated to 2-3 cm rms. The Navy has delayed acceptance of the satellite from the vendor pending demonstration that the mission could function well without the radio tracking system. The mission is now viewed as working well and acceptance is anticipated in early 2001. Once the spacecraft is accepted, the project will most likely request that tracking status be moved from Campaign status to the routine ILRS priority list.
Beacon C
Minkang Cheng reported on the status of the Beacon-C Campaign to support a multi-satellite study of the secular variations in the Earths gravity field (see Attachment 24). Beacon-C improves the separation of the zonal rates and is used in the determination of terms in the static gravity field. SLR is averaging about 15 passes per day. Five-day orbital fits are now running about 10cm. Additional improvements are anticipated. The present campaign was scheduled to conclude at the end of October, but Dr. Cheng has requested that it be extended through 31 December 2001.
IGLOS/GLONASS
Werner Gurtner gave an overview of the IGLOS program (see Attachment 25). Two GLONASS satellites are currently being tracked by the ILRS. A third was being tracked but had health problems in August, and tracking was terminated at the request of IGLOS. Three new GLONASS satellites were launched in October. IGLOS plans to request that one of those satellites be tracked with SLR. An IGLOS Pilot Project is being planned.
Upcoming Missions
ADEOS-II
Takashi Uchimura gave a presentation on ADEOS-II (see Attachment 26). ADEOS-II will carry five Earth observation sensors: Advanced Microwave Radiometer (AMSR), Global Imager (GLI), Improved Limb Atmospheric Spectrometer (ILAS-II), SeaWinds, and Polarization and Directionality of the Earths Reflectance (POLDER). It will use GPS and SLR for precision tracking. At an inclination of nearly 90 degrees, the spacecraft will cover nearly all of the Earths surface.
The SLR is required of POD to support the ground sensors, to help refine the gravity field and other satellite force models. Orbit requirements are 1 meter (3D) positioning of the satellite. Protrusions on the nadir facing surface will cause some obscurations to ranging activities and are of concern. Launch, originally scheduled for late 2001, has been postponed until early 2002 pending investigation of a recent launch vehicle failure. The satellite will require intensive tracking during an initial 3-month validation phase and then a schedule of periods of intensive tracking during each six-month cycle.
ENVISAT
Bruno Greco reported on ENVISAT (see Attachment 27) which is an enhanced follow-on for the ERS Mission. ENVISAT will monitor ocean circulation, mean sea level, ice thickness, and land surface properties. The mission will have the same ground tracks as ERS and will lead ERS-2 by about 30 minutes. The combination of DORIS and SLR is required for altimeter calibration and POD. The mission needs continuous tracking, but the highest priority is required during the six-month ENVISAT Commissioning Phase. Launch is scheduled for June 2001. Two additional satellites requiring SLR tracking are in the pipeline: Cryosat (2003) and GOCE (2005).
JASON
John Degnan reviewed the status of JASON (see Attachment 28). Jason, the TOPEX/Poseidon follow-on, will use a radar altimeter and a microwave radiometer to monitor global ocean circulation, monitor the air-sea interaction, improve climate predictions, and monitor ocean eddies. The objective of the mission is to monitor mean sea level to a few cm over a period of 3-5 years. The complex of GPS, DORIS and SLR will provide the necessary POD. The ILRS Governing Board has approved SLR tracking. Launch is scheduled for March 2001.
GRACE
Bob Schutz reported on the Grace Mission (see Attachment 29). The two-satellite GRACE mission will use K-band satellite-to-satellite ranging, GPS, accelerometers, and star cameras to obtain high-resolution mean and time-variable gravity field mapping of the Earths gravity field. SLR will provide POD validation. Tracking scenarios are under investigation to optimize tracking on the two satellites that will be separated by about 230 km. Launch is scheduled for November 2001. Each satellite has a CHAMP-like LRA. Many on-board systems were validated on CHAMP.
ICESAT
Bob Schutz also gave an account of the Geoscience Laser Altimeter GLAS System (GLAS) on ICESAT (see Attachment 30). GLAS is intended to measure changes in the polar ice balance, land topography and atmospheric characteristics. POD will be provided by GPS and SLR. Launch is scheduled for December 2001. The 3- 5 year mission will start with a four-month verification phase. A concern of GLAS detector damage by SLR near GLAS boresight is under study.
VCL
Mark Torrence reviewed the status of the Vegetation Canopy Lidar (See Attachment 31). VCL will use multiple laser altimeters to map the Earths vegetation canopy and surface topography. The mission is being launched to characterize land cover for terrestrial ecosystem modeling, monitoring and prediction, for climate modeling and prediction. POD requirements, less that 30-cm radial accuracy over a 30-hour arc, will be provided by GPS with SLR as secondary tracking. SLR will also support system calibration and validation. Launch is planned for early 2002. A Tracking Support Request form has been submitted to the ILRS.
STARSHINE
Amey Peltzer gave a presentation on Student Tracked Atmospheric Research Satellite Heuristic International Networking Experiment (STARSHINE), an NRL sponsored program to stimulate interest of students in space science (see Attachment 32). STARSHINE-1, launched in 1999, was a spherical satellite that carried nearly 900 small mirrors polished by students from around the world. Once launched, the network of over 20,000 students from 18 countries tracked the satellite through the glinting of sunlight off the mirrors and networked the data collection over the Internet. The students used the observations to calculate air drag, solar activity, and other orbit related properties. The program was a great success. NRL is now planning STARSHINE-II, which will have a system to spin the satellite to improve the flash rate and could include a few laser retroreflectors to introduce the students to SLR. The satellite is being built from spare flight hardware. Students are again polishing mirrors. NRL is soliciting donations of at least twenty 1 1.5 cm laser retroreflectors to include on the satellite. If the retros materialize, the ILRS will be asked to participate with SLR tracking and hosting some students at SLR sites. Launch is being planned from the Shuttle for October 2001.
Joint IVS/ILRS/IGS Working Group
Graham Appleby reported on the activities of the Joint IVS/ILRS/IGS Working Group (see Attachment 33). The group was formed to see if the combination of VLBI, SLR and GPS could be used to better understand the uncertainty in the location of the phase center of the GPS transmitter, which may be as large as a meter. Graham Appleby and Richard Biancale, the representatives from the ILRS, attended a Working Group meeting in Koetzting, Germany in February. The group agreed that they should measure (1) the mean phase center location of the full array and (2) the relative effects of the individual radiating elements using the VLBI and the SLR to accurately determine the satellite center-of-mass. They are now working on estimations of potential accuracy and determining the technical roadblocks to working this through.
ILRS Annual Report for 2000
Now that the ILRS Annual Report for 1999 is in printing, Mike Pearlman outlined the plan for the preparation of the ILRS Annual Report for 2000 (see Attachment 34). Whereas the first Annual Report contained significant background and detail, subsequent annual reports will be viewed as opportunities to update information in a concise manner. The report for 2000 must be brief and concise, use the same version for both the hardcopy and web editions, make liberal use of web site links and references, and be available on fast turnaround. A draft outline will be circulated for comment.
Next Meeting
The next ILRS General Assembly will be held in conjunction with the EGS Symposium in Nice, France during the week of March 26 30, 2001, most probably early in the week. The Governing Board meeting will probably be held during the previous weekend, and it is suggested that the Working Groups consider also holding their meetings during the previous weekend, prior to the General Assembly.
Editor's Note: If you would like to receive the attachments, please send an email request to Mike Pearlman (mpearlman@cfa.harvard.edu). These minutes are also available in Microsoft-Word.