PNT Through Optimised LEO Constellation and INS

Abstract

Mainstream Global Navigation Satellite System (GNSS) which are primarily used for Positioning, Navigation and Timing (PNT) estimation faces intentional and unintentional threats such as spoofing, jamming, multipath. This vulnerability is against the efforts to increase in supply of robust, accurate, safe GNSS systems. On the other hand, state of art research on PNT estimation based upon the Signal of Opportunities (SoOP) from in-orbit Mega Constellations from private enterprises such as Starlink, OneWeb, Kuiper, Iridium which are mainly used for various applications such as internet, IoT, telecommunication hint towards the Low Earth Orbit (LEO) satellites to be recognised as the promising positioning system. Small dimensions, versatility, short development period, high return-to-cost potential, high speed, proximity to the Earth, the Doppler based positioning make LEO systems good candidates for possible positioning solutions which are complimentary to the existing Medium Earth Orbit (MEO) GNSS and terrestrial navigation in the near future. In this context, this paper presents the definition and evaluation of preliminary positioning solutions by designing a dedicated LEO constellation optimized using a Genetic Algorithm (GA). Furthermore, this paper demonstrates that such optimized constellation can provide a navigation service exploiting integration with Inertial Navigation Systems (INS) using Extended Kalman Filter (EKF). In particular, positioning accuracy for static and dynamic user scenarios has been assessed using standalone optimised LEO and LEO+INS integration.