International Laser Ranging Service

ILRS NEWG Meeting (Matera 2000)

Matera, Italy
November 13, 2000

Attendees: Werner Gurtner, John Degnan, David Carter, Yang Fu Min, Mike Pearlman, Van Husson, Ulli Schreiber, Georg Kirchner, Graham Appleby, Buddy Donovan

Observers: Roland Schmidt, Anja Schlict, Stephan Reipl, Roger Wood, Francis Pierron, John Luck, Scott Wetzel, Matti Paunonen, Jocelyn Paris, Vince Noyes

John Luck is added as a new Working Group member. Georg Kirchner replaces Wolfgang Schlueter as Deputy Chair.

Station Logs

Van Husson reported that 34 stations have already submitted their station logs. The logs are accessible on the CDDIS. Logs from another 10-12 stations are still outstanding. It was agreed that:

• The site log data should be placed into a master file with search capability; a spreadsheet format might be a simple venue. (Action: Van Husson)
• Subject experts will be recruited to review the site log material for consistency and completeness. (Action: Werner Gurtner)

Normal Point Data Submission

A document on Options for Normal Point Data Submission Procedures for the stations including backup modes has been distributed and placed on the ILRS web site. Zimmerwald has set up an email site as a backup for EDC.

Calibration Workshop in Florence

Ulli Schreiber reviewed some of the important conclusions from the SLR Calibration Workshop held in Florence in September 1999. Thermal expansion, humidity, and cable replacement issues need more attention.

The draft report from the Workshop has been sent out to the session chairpersons for review. It will be circulated next to the Working Group members.

Link Budget Calculation

Stephan Riepl presented the latest version of the on-line satellite link calculation. He was requested to (1) include several satellites that were missing and (2) define a process whereby information updates and information on new satellites could be routinely added to the link calculation files. It was suggested that this activity should be coordinated with the Missions Working Group, which should be responsible for furnishing current information.

Working Group Charter

In response to the maturing role of the Networks and Engineering Working Group, Van Husson has drafted a revised working group charter for review. It was suggested that the revision should maintain as much of the original wording as possible and show changes on a line by line (red line) basis. Van will rework the charter in this manner to produce a draft for circulation. This may also have an impact on wording in the Terms of Reference.

It was noted that the charter for the Networks and Engineering Working Group and the Data Formats and Procedures Working Group can be interpreted as having some overlap. John Degnan’s interpretation places the diving line between the Operations Centers and the Data Centers. However, Data Formats and Procedures has responsibility for all data formats. It was noted however, that the working groups are working very closely together and that each is generating ideas based on vast experience. It was agreed that the two groups should continue to work together, particularly in areas of mutual concern.

Qualification for ILRS Participation

A fundamental issue with the charter is the need to specify the qualifications for

• ILRS stations to remain a part of the ILRS network and
• New stations to join the network.

Some stations are not performing at an acceptable level and several new stations would like to join. The need is actually more general for the ILRS, since some of the other entities are also performing above and some below their current designations. A small study group consisting of Mike Pearlman, John Degnan, Van Husson, Graham Appleby, and David Carter was formed to draft criteria for continued station participation and for the acceptance of new stations. They will have a draft position available by February 1. The group will also examine the qualifications for other ILRS entities.

Email Exploders

URGENT has been established at CDDIS as a rapid means of contacting stations and operations centers. The CB will send out a note asking Stations Managers to facilitate the use of URGENT in their operations. (Action: Mike Pearlman)

In addition to URGENT, other new ILRS exploders have been established. The Central Bureau will

• Monitor the use of the exploders to see that they are being properly used; and
• Issues a notice reminding ILRS associates of the role and method of accessing each of the exploders.

Performance Reports

It was suggested that we try to consolidate the station performance and status reports to give a single on-line integrated report with the most up-to-date information for both stations and users. (Action: Mike Pearlman and Van Husson).