Журнал: Proceedings of the 23rd European VLBI Group for Geodesy and Astrometry Working Meeting Proceedings of the 23rd European VLBI Group for Geodesy and Astrometry Gothenburg, Sweden
Ключевые слова: VLBI, radio telescope, phase calibration, PCAL, Svetloe station
Using multi-tone phase calibration in VLBI observations can potentially give better results than the conventional single-tone technique. At the same time it increases the requirements to phase calibration (PCAL) signal quality. Distortions of PCAL signal can eliminate all benefits of multi-tone calibration up to making it completely unusable. To prevent this and to examine the condition of PCAL signals at "Quasar" VLBI network stations we performed a series of test measurements with RT-32 radio telescopes. The measurements included estimation of amplitudes and phases of all PCAL tones in all channels in standard S/X geo mode and their dependence on the antenna elevation. The results were used to perform troubleshooting on the stations which has already resulted in a significant improvement of PCAL signal quality which, in turn, is expected to lead to better calibration results, both singleand multi-tone. The paper presents brief report of the measurements taken and the results achieved.