Minutes from CSTG SLR/LLR Subcommission Meeting (12/95)

Berne, Switzerland

Michael Pearlman/CFA

The CSTG SLR Subcommission Meetings was held at the University of Berne December 05-07, 1995. John Degnan chaired the SLR Subcommission Meeting. The host for this meeting was the Astronomical Institute of the University of Berne. The highlights from this meeting are as follows:

1. SLR needs to improve its effectiveness and its utility. We need to focus on (1) Task sharing among stations to improve satellite coverage, (2) Relocation of station to fill in the gaps in global coverage, (3) Improved data quality, and (4) automation to reduce personnel and increase temporal coverage.
2. A CSTG working group is being formed to develop the rational for the Network of Fundamental Geodetic Reference Stations and Stations Clusters proposed by Prof. Beutler to provide system integration for space geodetic techniques and as a basic tool for improvement in measurement capability.
3. The role of the SLR Subcommission is to:
   • Inform the stations and Data Centers of new SLR satellite missions with descriptions, schedules, and tracking requirements, prior to launch,
   • Schedule and prioritize tracking requirements,
   • Review network performance on each satellite,
   • Periodically review appropriateness of satellite requirements and experience of data usage and application.
4. Lunar Laser Ranging has been added to the Subcommission (now SLR/LLR Subcommission) and an LLR Representative has been added to the Steering Committee. Peter Shelus was elected as the LLR representative.
5. The current Steering Committee will remain as presently constituted; there will be no formal term limits for Steering Committee members; each of the regional areas will choose its own representatives and decide when to change; Members-at-Large will be elected (or reelected) periodically at the Subcommission meeting held in conjunction with the Laser Workshop.
6. Major changes to the CSTG SLR format will not be made at this time, however small changes are being made to (1) accommodate near infrared wavelengths and (2) include a data release sequence index.
7. In order to improve SLR tracking on GPS, RGO has agreed to generate weekly IRVs as necessary and daily time bias updates from the GPS broadcast elements and make them available on FTP and on EDC mail. RGO has also offered to provide daily timing updates for the NASA IRVs to ATSC for distribution. Alan Murdoch/ATSC will work with Andrew Sinclair to issue a standard GPS product based on the GPS broadcast elements for general acquisition use.
8. Data Centers need no longer archive quick-look engineering data. All SLR field generated normal points are now available from both CDDIS and EDC.
9. We agreed that if new missions want international SLR tracking support, they must approach the network members through the SLR Subcommission to make such arrangements.
10. Field Generated Normal Points (FGNP) are now the standard product. Stations must make every effort to include final (or best available) timing and meteorological corrections in their FGNP data. EDC, as well as CDDIS, now has the FGNP data files on all satellites.
11. Except for specialized needs, full-rate data archiving will cease at the CDDIS and the EDC. Stations will be requested to maintain there own full-rate files for 1 year, and then they are free to dispose of them. Those wishing to use the full-rate data are welcome to contact the stations. We plan to cease archiving and transmitting full-rate data on April 1, 1996.
12. The peak versus mean issue for returns from the single photon systems is still not resolved. A survey will be done to determine what the stations are currently doing. In the meantime, stations should not correct range measurements to the distribution peak.

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Last modified date: Friday, November 05, 2004
Author: Carey Noll
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