Gritsenko Andrei

In1985, Gretsenko graduated from A.F. Mozhaysky's Military-Space Academy. From 1985 to 1991, he worked at the Baikonur Cosmodrome, servicing ERS control systems. From 1991 to 2001, post-graduate military course and service at scientific research divisions of A.F. Mozhaysky's Military-Space Academy. From 2001 to 2014, he worked for a NIIR Branch Office. Since 2014, he is CEO of Severnaya Korona Information Space Center. He has extensive experience in planning ground-based radio systems, developing satellite systems and facilities for various use, as well as special software.


“SPHERE” CONGRESS SECTION Satellite Communication and Broadcasting Systems
«Analyzing main characteristics of NGSO systems through mathematical modeling»
It is shown that the main features of future and existing non-geostationary (NGSO) satellite systems can be evaluated, first of all, through mathematical modeling.
It has to do with the fact that the spatial position of satellites is constantly changing in NGSO systems. The change of satellites' position with respect to ground-based subscriber stations causes two main problems:
  • change in operating conditions inside an NGSO system itself;
  • destructive impact (interferences) on the work of other GSO and NGSO satellite radio systems while operating on shared frequency bands.
  • The repositioning of satellites causes changes in conditions of systems’ functioning. In particular, the position of instant radio-visibility zones is constantly changing. If a system doesn’t use inter-satellite links, the instant footprint of a satellite is formed only if it enters the radio-visibility zone of a terrestrial gateway.
    That is why the instant radio-visibility zones corresponding to satellite locations at a single point of time don’t bear the system information. It is necessary to use assured radio-visibility zones (ARVZ) clearly showing the territory of the Earth’s surface, where within a set percentage of year’s time at required angles of location we observe a certain number of satellites.
    The particular practical value belongs to ARVZ of NGSO systems, which don’t use inter-satellite links to serve subscribers, and the communications are proved via a network of terrestrial gateways. They include almost all deployed and future telecommunications systems: Exprss-RV, Skif, Gonets, Marafon, as well as Kuiper, Starlink and OneWeb. They show where the communication and data transmission services of required quality can really be provided. The study presents ARVZ of all main IoT and broadband access satellite systems. The report demonstrates specifics of the deployment of Starlink and OneWeb constellations.
    The second problem is an EMC problem between GSO-NGSO and NGSO-NGSO networks. If the issue of GSO-NGSO EMC is highly enough covered in publications, the issue of NGSO-NGSO EMC is currently under study. It’s a commonly shared view that two NGSO systems operating on a single frequency band are generally not compatible.
    The study gives results of modeling, which evaluated a signal/interference ratio on the input of a subscriber terminal receiver of one of the NGSO systems that is interfered by another NGSO system. It also draws conclusions concerning conditions of joint operations of two NGSO systems.