ONGOING OPERATION AND PERSPECTIVES OF SIMPLE VLBI NETWORKS OF GEOSTATIONARY SATELLITES MONITORING

Анотація

The report is dedicated to introducing
the operation and prospects of further development of
simple VLBI networks which were created in Ukraine,
Latvia, and China for monitoring the orbital information
of geostationary satellites. The Ukrainian-Latvian network
consists of five stations located in Mykolaiv, Kharkiv,
Mukacheve, Ventspils, and Rivne, and it operates since
2015. The Chinese network consists of three stations lo-
cated in Shanghai, Duyun, and Urumqi, and it formally
carried out a network observation from June 2019.
The networks have identical hardware and software. The
main principle of the operation of the networks learned
from the VLBI is correlation analysis of broadband noise-
like signals of satellite television DVB-S, which are emitted
by satellites and synchronously received by the stations of
the networks. Single-frequency GPS receivers are used for
the synchronizing of network stations. Time difference of
arrival (TDOA) between the signals paths from the identical
TV satellite to different stations is obtained via using corre-
lation analysis. These values of TDOA are used to deter-
mine orbital elements of the tracked satellites which are
given in the report. Notably, the cost of one set of station
equipment does not exceed $2000, and the current operat-
ing costs are about $50 per day.
The prospects of further development of the simple
VLBI networks include a) the possibility of continuous
independent non-invasive high-precision determination of
the position of arbitrary active satellites (especially im-
portant in the case of their co-location), b) the possibility
to fully automate targeting and operation, c) the possibility
of using accumulated observational data to solve scientific
geophysical and astronomical tasks, d) relatively few
funds necessary for the modernization and operation of
the networks.