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13th International Laser Ranging Workshop
"Toward Millimeter Accuracy"

Station Performance Evaluation (C. Luceri and R. Wood)
Session Summary

Title Primary Author
MyStationPerformance.COM Van Husson
The Precise Data Processing in MCC Analysis Center Vladmir Glotov
The stability of the SLR stations coordinates determined from monthly arcs of LAGEOS-1 and LAGEOS-2 laser ranging in 1999-2001 Stanislaw Schillak
Range Bias vs Applied System Delay Toshimichi Otsubo
Absolute and Relative Range Bias Detection Capabilities Van Husson
Status of the KACST SLR Program -- Past, Present and Future Turki Al-Saud
Results of the triple laser ranging collocation experiment at the Grasse observatory, France (September - November 2001) Joëlle Nicolas

The issue of the continuous and rigorous evaluation of observing station performance, as seen from the quality and stability of data obtained by stations, has gained an increasingly high profile in recent years. The ILRS has played a crucial and central role in raising awareness of the importance of such evaluation and in setting standards. Attention has concentrated on two main areas: feedback to stations from ILRS and analysis centers; self-assessment at stations. Both are reflected in the papers presented in this session.

V Husson outlined an ambitious concept: MyStationPerformance.COM - a friendly, online, expert system exploiting an extensive central database to provide enquirers with a wide range of standard tools (time-series, diagnostics, analyses, etc.) to obtain instant answers to many quality control questions. It will require a lot of work and is likely to develop slowly over time. It is intended to supplement, not replace, on-station evaluation.

S Schillak showed how his monthly determination of station coordinates from Lageos 1 and Lageos 2 SLR orbits for the years 1999-2001 provides continuing feedback of station stability, identifies problems and measures improvements.

T Otsubo extended his powerful technique of correlating range bias with other system parameters to examine applied system delay as a discriminant of data quality and consistency. He recommended more system monitoring at stations as a prerequisite for self-assessment and on-station review of operational practices.

V Husson continued this theme showing how comparisons of range biases computed by different analysts (from the same data sets) provide the means to assess varying modelling techniques as well as speedy identification of stations’ problems.

T Al-Saud reported recent progress at the SALRO station, a very welcome renewal of laser ranging activity at this critical site in the global network. It was good to see high stability, steadily increasing data volume and concrete plans for future improvements.

J Nicolas demonstrated the benefits available from a unique triple SLR collocation at Grasse during 2001 Sep-Nov. She examined range biases from common observations of Lageos, Starlette, Stella and Topex. These revealed subtle differences between the three systems and compellingly reinforce the importance of gaining a full understanding of centre-of-mass corrections, calibration and detector effects in each individual system.

It is clear that there is a future need to develop:

  • More effective central help and advice;
  • Better coordinated feedback from analysts;
  • More regular, more frequent, more comprehensive monitoring at stations.

Our assessment is that there is continuing good progress in all these activities and urge stations and analysts to keep up the good work!


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Last Updated: February 23, 2024



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