Integration of R-Mode MSK Broadcasts and PVT Solutions for Stable Clock Synchronization in the Baltic Sea

Abstract

Time synchronization plays a critical role in modern maritime navigation, enabling precise positioning, coordination, and safety. While Global Navigation Satellite Systems (GNSS) remain the foundation for positioning and timing, vulnerabilities such as jamming and spoofing,especially in the Baltic Sea, have driven the development of complementary systems such as R-Mode. This thesis investigates time extraction methods from Minimum Shift Keying (MSK) signals within the R-Mode system, evaluates synchronization accuracy, and explores techniques for stabilizing a local clock oscillator against remote atomic clock references to obtain a stable, up-todate clock. The work combines theoretical analysis, GNU Radio implementation, and simulation to demonstrate the feasibility of resilient, synchronized maritime navigation beyond sole GNSS dependence.