IGG Scientific Seminar – Dr. Tomasz Kur
The IGG is pleased to invite you to a scientific seminar, which will be held remotely using the Zoom platform. The presentation entitled "The application of inter-satellite links in orbit determination of GNSS satellites: simulation studies" will be given by Dr. Tomasz Kur from our institute.
The seminar will begin on Thursday 25 May 2023 at 09:00 AM (CEST).
Join the Zoom meeting: ZOOM LINK
Meeting ID: 811 427 0260
Access code: igig
The application of inter-satellite links in orbit determination of GNSS satellites: simulation studies
Dr. Tomasz Kur, Institute of Geodesy and Geoinformatics, UPWr, Poland
To improve the quality of navigation satellite orbit determination it is planned to equip the next-generation satellites with new on-board instruments, e.g., optical clocks with increased precision, accelerometers to measure non-gravitational accelerations, and inter-satellite links (ISL).
In this presentation, first the current state-of-art of ISL is discussed. Then, main results and conclusions of simulation studies on the ISL use in the Galileo constellation performed by the author are summarized. Evaluation of simulation results of the ISL in the orbit determination procedure is presented in terms of (1) inﬂuence of the used connectivity scheme and (2) impact of the ISL for diﬀerent observation parameters and weighting methods. First point concerns general geometric analysis of selected connectivity schemes, dependence of the results of the orbit and clock estimation on the geometry of navigation constellations (i.e., its Walker deﬁnition). Second issue regards the impact of the inter-satellite links in different observation scenarios including number of used ground stations, ISL measurement intervals, and relative weighting of the GNSS and the ISL observations using variance component estimation. Additionally, the assessment of ISL range bias estimation with alternative ISL calibration are considered.
The work aims at determining the possible gains from the new type of observations, but also to develop a methodology concerning adaptation of the least squares procedure for orbit determination with the use of the ISL with evaluation of the relative weighting methods. The results show high eﬃciency of the inter-satellite links, especially in diﬃcult observation conditions, which in turn may contribute to better reliability of the navigation constellations.