2001 Satellite User Requirements Survey

    (1) the level of interest in each of the satellites on the Priority List,
    (2) what analysis work is being done with the data, and
    (3) whether we are being responsive to the user needs.

The most recent survey was taken in March-April 2001 with the previous one being in 1996. The survey was conducted to ensure that the data acquired is being used and that mission requirements are being met. The complete survey (i.e. questions, results, analysis, and synopses) are located at:

satellite_survey_2001.pdf

In the 2001 survey, the ILRS Analysis and Associate Analysis Centers were asked a set of 9 questions. Seventeen SLR and three LLR centers responded. Satellite applications included EOP, reference frame, gravity field, station position and motion, relativity tests, precision orbit determination (POD), quality control (Q/C) for stations, spacecraft modeling, and technique intercomparisons. Lunar applications included EOP, relativity, lunar gravity field, lunar ephemeris, tidal accelerations, and other lunar science. Synopses of the center responses are included in Appendix 1 of the complete survey (.pdf file).

2001 Survey Results

The data from each of the satellites currently being tracked by the ILRS stations is being used by at least three centers. Most of the satellites are being used by six or more centers, and many of the centers expect to use the data from the new LEO satellites such as Jason and Envisat as soon as it is available. In general, the users want more data, but the biggest issues appear to be with the high satellites and with the weekend and holiday outages on LEO satellites. Data coverage is improving in the Southern Hemisphere, but it is still weak. Tahiti and Arequipa are still disappointing. Data accuracy from the well performing stations is adequate, but there are still too many weak, unstable stations. Perhaps the ILRS should issue a screened data set. Data products should be more standardized and satellites should be better characterized. We need to implement more effective tracking strategies to be more effective. Improvements in stations documentation and eccentricities are underway.

Responsible Government Official: Carey Noll
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