Perspective of the Radio Interferometric Tools Using for High-Precision Trajectory Measurements of Geodetic and Navigation Field

D. A. Gavrilov, I. V. Sakhno, I. F. Surkis

Transactions of IAA RAS, issue 71, 26–33 (2024)

DOI: 10.32876/ApplAstron.71.26-33

Keywords: navigation task, very long baseline interferometer, VLBI, spacecraft, correlator

Abstract

One of the possible ways to spacecraft orbits determination precision improvement is the very long baseline interferometry (VLBI) method using. It allows to add high-precision angular (or difference-ranging) measurements into the system of equations for determining the initial conditions of the spacecraft state vector, and, in the long run, increase the accuracy of navigation support. To estimate the accuracy of measurements the experiments, of GLONASS spacecraft observations by Quasar VLBI Network radio telescopes have been carried out. The observations were processed by two methods: using Matlab software in the mode of a single antenna and difference signals, codes were obtained in the single antenna and difference signals modes, while group and phase delays were obtained by the standard software correlator of Quasar VLBI Network “RASFX”. A comparison of the results is given. The code delays precision of 400– 500 mm and phase delays precision of 0.2– 0.3 mm were obtained when processing a short (second) observation interval using Matlab in the single antenna mode. In the next 300-second experiment, using a one second accumulation period, Matlab obtained the precision of difference signals of 75.1 mm code and 0.5 mm phase delay. The same experiment was processed by the RASFX correlator, group delays with a precision of 23.8 mm and phase delays with a precision of 0.5 mm were obtained. There is a good agreement between the delays obtained by Matlab and those by the RASFX correlator. High instrumental precision of delays has been achieved, which allows us to conclude that further research in the field of VLBI technologies in application to spacecraft trajectory measurements is expedient.

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