Evaluation and Improvements of the Calibration of a TWSTFT Station Using SATSIM; Conference paper

摘要

As part of the Galileo project of Early Trials on Time Synchronization Techniques and Calibration Issues, the TWSTFT automated station delay calibration system using a special Satellite Simulator developed by VSL (SATSIM) at NMi-VSL was evaluated. This was done to verify the obtainable uncertainty level with this technique. The results of the evaluation will be presented. The stability of the station delay calibration has been reported earlier. The problem of reflection in cables used for GPS, Glonass, and TWSTFT has been reported earlier and may cause systematic errors and temperature sensitivity. The SATSIM system has now been checked for these reflections by revealing them by a new method with varying frequencies. Some imperfections were found and corrected; the final uncertainty results are now at the nanosecond level.