Introduction
The Laboratory for Marine Geosciences at the French University of the Pacific, in collaboration with the Centre National d'Etudes Spatiales (CNES), the Shanghai Astronomical Observatory and the National Aeronautics and Space Administration (NASA), hosted the Second International Meeting of the Asian-Pacific Space Geodynamics (APSG) Program on May 12-16, 1998 in Tahiti, French Polynesia. The APSG program was organized to stimulate international collaboration between scientists and experts in measurement techniques who are working in the Asia-Pacific region to (1) advance research in crustal motion, deformation, and sea level change; (2) provide basic information on the causes of and means for mitigating natural disasters; (3) enrich our knowledge of the dynamics of the Earth, (4) promote international scientific exchange and cooperation, and (5) contribute to raising the scientific research level in the developing countries.
Background
At its first meeting in Shanghai in May 1996, the APSG established:
The first meeting provided a venue for scientists working in the relevant disciplines in the Asia-Pacific region to meet, discuss their work, and plan activities that would benefit from a synergistic umbrella supported by key institutions and agencies in the region.
The Meeting
The objectives of this second meeting were to:
The plan for the meeting was to:
Fifty-two participants from Australia, China, France, French Polynesia, Germany, Indonesia, Japan, Hong Kong, Korea, New Caledonia, Russia, Taiwan, and the United States attended (see the Attendance List in Attachement 1). All participants in the meeting were required to join a Science Working Group or a Measurement Technique Panel. Each was asked to give a short presentation on his work in the region along with current plans (see the Agenda in Attachment 2 and the List of Papers in Attachment 3). Conveners of the Science Working Groups were asked to report on the progress-to-date in organizing their Working Groups and Panels, and in the development of their charters and plans. All Science Working Groups and Measurement Panels were required to provide a draft summary report addressing the above issues before the close of the meeting and a final version 30 days later. Copies of the draft reports are included in Attachments S1 -- S3 and M1 -- M5.
In their deliberations, the Science Working Groups were asked to address the following questions:
The Measurement Technique Panels were asked to address the following questions:
Trip Report
Michael Pearlman, John Bosworth, David Carter, and Chopo Ma travelled to Tahiti on May 10/11 to participate in the APSG Meeting and the dedication of the new satellite laser ranging station at the campus of the French University of the Pacific. The meeting was held at the Maeva Beach Hotel just south of downtown Papeete, near the Faaa Airport and the University campus.
Pearlman worked with Prof. Alain Bonneville from the Laboratory to organize the meeting, develop the announcement circulars and invite participants. Pearlman and Bonneville also chaired the meeting. Chopo Ma was the convener of the VLBI Measurement Technique Panel. John Bosworth and David Carter were active members of the SLR Measurement Technique Panel.
Monday, 11 May
We arrived early in the morning. Alain Bonneville and Mike Pearlman met at the University to review the agenda and other last minute details for the meeting. At 4:00 pm, we met with the Conveners for the Science Working Groups and the Measurement Technique Panels to organize the presentations in the sessions. In the evening we retyped the "latest version" of the meeting agenda and program.
Tuesday, 12 May
After meeting registration and welcoming talks, the Working Groups and Panels met to begin their work. In response to popular demand, the Saturday session was cancelled to free up the day in exchange for a "group promise" to work evenings and still complete the draft reports by departure time.
The Special Seminars scheduled for the afternoon were cancelled and the time was allocated for tours of the station.
At 5: 00 pm the Station Dedication was held. Speakers included: Patrick Howell, Minister of Health and Research for French Polynesia, Jean-Louis Counil for CNES, Miriam Baltuck for NASA, Prof. Pierre Verin for the French University of the Pacific, and Jean Pierre Gratier for the French Ministry of National Education for Research and Technology. There were tours of the station and an opportunity to mix with a number of the University people and to watch the ranging system operate. The station is now operating with an ATSC training engineer, two Tahitians, and a French military detailee.
Wednesday, 13 May
On Wednesday morning, eleven papers were given in the Science Session on Crustal Motion and Dynamics of the Tibetan Plateau, convened by Zong-jin Ma and Brad Hager. In the afternoon, seven papers were given in the Science Session on Crustal/Tectonic Motion of the Western Pacific Volcanic-Seismic Belt convened by Yehuda Bock and Makato Murakami. Several of the nine papers in the Science Session on The Impact of Sea Level Variations on the Asia-Pacific Region convened by Wolfgang Scherer and C.K. Shum were also given.
Thursday, 14 May
Thursday morning we allocated an hour to begin discussions on network configuration, station participation and data policy. It was a good idea to get these issues started as early as possible so that they would be further developed by the close of the meeting.
The remaining papers in the Science Session on The Impact of Sea Level Variations on the Asia-Pacific Region were given, and nine papers were presented in the first Measurement Technique Panel Session on Radio Techniques convened by Stephane Calmant and Pascal Willis.
In the afternoon, there were seven papers in the Panel Session on Gravity convened by Francois Barlier and Houtze Hsu, five papers in the Panel Session on SAR convened by Miriam Baltuck, nine papers in the Panel Session on SLR convened by John Manning and Richard Biancale, and eight papers in the Panel Sessions on VLBI convened by Chopo Ma and Martine Feissel.
In the evening, Miriam Baltuck and Mike Pearlman attended the APSG Management Board Meeting.
Friday, 15 May
On Friday morning, the Science Working Groups and Measurement Technique Panels were free to meet and continue work on their report. Most of the Measurement Technique reports were either completed or well on their way toward completion, and some members of Panels were able to join the Science Working Groups.
In the afternoon the Science Working Groups made their final presentations, and then discussions on APSG issues were held (see below).
Saturday, 16 May
Saturday was available for Science Working Groups and Panels to complete their draft reports. The reports are included as attachments S1 -- S3 and M1 -- M5.
Renaming of Working Groups and Panels
Procedures, Standards, and Reference Frames
It was agreed that standardization of reference frames is a fundamental issue for comparison and integration of analysis results by different groups and that it should be accommodated within the Measurement Technique Panels. (Other programs such as WEGENER are still grappling with the issue.). In more general terms, we need a means organizing procedures and standards which should encompass reference systems, formats, reporting procedures, etc. Such an activity of course should make every effort to use existing standards and resources before inventing something new.
It was agreed to establish a Measurement Technique Panel on Procedures and Standards. Martine Feissel and Claude Boucher agreed to be conveners of the Panel and to begin structuring the reference frame issue.
Within standards and procedures, we need to include tide gauges and, in particular, how we link the altimeter foot-print to the tide gauges.
Core Station Network
In order to get position and velocity measurements that can be related from one experiment to another and from one geographic area to another, we need a reference network, or a network of fixed stations that we share among all of the measurement activities. The lack of such standardization has plagued other programs such as WEGENER which now, after close to 15 years, are forced to address the issue.
It was agreed that we needed a permanent Core Network of GPS stations covering the region with spacings in the neighborhood of 1000 and 1500 km to provide the stable reference for regional measurements. The Science Working Groups have each developed candidate networks in their region incorporating presently operating IGS stations, presently operating non-IGS stations, projected stations, and general areas where new stations are needed. All of the permanent sites in these regions should be encouraged to join APSG, and the full Core Network should be assembled from the pieces "recruited" by the Science Working Groups. Recognizing that we will have to overcome many political realities in building the Core Network, we should:
The Science Working Groups should contact the stations known to be operating in their region to establish and stimulate their level of participation.
Jeff Freymueller, with input from Mike Bevis, Brad Hager, Shuhua Ye, Jungong Chen, and Yehuda Bock, agreed to provide a write-up for the report on the development of the Core Network with the "proper flavor". Jeff and Mike will also compose a letter for approaching new GPS stations partners.
APSG Data Policy
There is presently very good data exchange for non-GPS techniques. Data from some of the permanent GPS stations is available, but there are still many large gaps and the present GPS data flow to international data centers does not provide an adequate Core Network. A considerable amount of data is presently withheld and probably only a subset, routinely provided on an expeditious basis, would go a long way toward filling out the Core Network. The rest of the data could be worked in at a later time. It was noted that there are probably stations that take data that are never analyzed.
It was agreed that the APSG should set up an integrated regional meta-data base for GPS stations that in the Asia-Pacific region. This meta-data base should:
Toward implementation, it was agreed that the Science Working Groups should be responsible for setting up meta-data bases in their own regions and that these would then be integrated.
We need to organize a mechanism (committee?) to set-up standards and provide overall integration for the meta-data base.
The Science Working Groups should contact the stations known to be operating in their region to establish and stimulate their level of participation (same as above).
It was pointed out that GPS is not the only data access issue. ERS-1/2 data are restricted even to those who are routinely providing tracking data which is essential for orbit maintenance C.K. Shum agreed to look into the matter.
1998 Measurement Campaign
The first APSG Campaign took place in late 1997. One of the main participants, GEODYSSEA97, was cancelled at the last minute due to the smoke conditions in Indonesia. John Manning was responsible for organizing the campaign and assembling the UN and APSG meta-data base for the campaign.
A measurement campaign will be held in the October-November 1998 timeframe using all systems then in place. Activities already planned for the region in this timeframe include:
Each program is to collect its own data and form its own meta-data-base with linkages to the relavant APSG Science Working Group. Results from this campaign should be reported at the next APSG Meeting in 1999 (see below).
Bernt Richter will check with BKG to verify that GEODYSSEA98 can be included.
John Manning and Sobar Sutisna will work to set up coordination of all of these activities within APSG.
The Campaign will provide an opportunity to assess the elements that would become part of the Core Network. All groups with tracking capability will be solicited by the relevant Science Working Groups and invited to participate in this time period. It was recognized that an informal approach at the working level by a Science Group or an involved research organization might be more successful than high level formal contact.
The Science Working Groups will have the option to adjust the interval of the campaign for its participants and the potential Core Stations that they approach to accommodate their measurement needs.
Call for APSG Participation
In addition to Core Stations, APSG needs to formalize other roles and participation including data centers, analysis centers, and operations/coordination centers to support its programs. The Science Working Groups were asked to seek interested parties within their membership to be more formally approached through an APSG wide Call for Participation. Such a Call would also help us gauge the interest of other organizations. It was suggested that the Science Working Groups issue letters (E-mail letters) to inform the community about the campaign and the opportunity to fulfill roles within the APSG. Aside from science entities, operational entities must also be approached for participation. Mike Bevis has offered to help write letters of solicitation.
We need to organize the solicitation process. Some key issues that need to be addressed:
Do we have sufficient consensus on the statements of scientific objectives to make a meaningful solicitation?
Have we adequately separated our scientific requirements from our means of implementation?
Should Science Working Groups review their own proposals and organize their own section or should this be done under a single APSG activity?
Communications and Information Distribution
We currently have a web site for APSG98 at GSFC, but an APSG program web site should be established in the Asia-Pacific region to maintain a bulletin board of activities and reports and as a general tool for planning and communication. Baki Iz agreed to work with the Shanghai Observatory to see if together they could develop and manage such a site. The posting of material from this meeting and a directory of APSG participants (individual) and stations would be a good place to start.
Baki iz and Shuhua Ye need to tell us if a Hong Kong Polytechnique University/Shanghai Observatory team can make this work and how they plan to get it established.
APSG Organization
Prof. Alain Bonneville was unanimously elected to the APSG Management Board as the representative of France and French Polynesia.
The formal organization of the APSG, as ratified at the Shanghai Meeting, was presented by Shuhua Ye (see Attachment 4). Since the Shanghai meeting however, the infrastructure functions have not been very visible and, as noted above, the Science Working Groups have at least temporarily assumed some of the infrastructure functions.
Now that the science definition is fairly well articulated, it is time to make the APSG organization more responsive to program implementation.
We might want to consider establishing a proactive implementation board made up of at least:
Whereas the current Management Board would provide overall guidance, political insight and organizational support, the Implementation Board would help manage and integrate the APSG activities and help provide regular oversight and continuity.
APSG Endorsements
It was agreed that recognition of APSG and APSG campaigns by the United Nations, IAU, IAG, and IUGG would strongly enhance opportunities for groups in many countries to obtain government support for their activities.
Shuhau Ye and Baki Iz will prepare and circulate a draft letter to the UN seeking recognition APSG.
Martine Feissel and Junyong Chen will prepare a proposal to send to IAG and IUGG asking that some connection be established with APSG.
Proposal to NASA
One way to attract more attention from NASA is to submit an APSG proposal in response to the periodic MTPE AO solicitations as did the WEGENER Program. The WEGENER Proposal included more than 80 organizations in 30 countries and was part of the basis for NASA's strong participation in the program. The schedule for the next NASA AO is not clear, but traditionally it has been issued annually.
If a proposal is going to be prepared for NASA, it will require someone to organize the pieces and pull it together
Next APSG Meeting (APSG99)
The APSG Management Board has accepted an offer from Dr. Teruyuki Kato from the Earthquake Research Institute at the University of Tokyo to hold the next APSG meeting at the International Symposium on GPS -- Application to Earth Sciences and Interactions with other Space Geodetic Techniques in Tsukuba, Ibaraki, Japan during October 18 -- 22, 1999 (see Attachment 5). A session on APSG would be included in the meeting and a venue for an APSG business meeting would be provided. All Science Working Groups and Measurement Technique Panels should report on their activities at this meeting. Makoto Murakami is on the organizing committee and should be contacted with further questions.
Resolutions