Salinity-Driven Variability of Ground-Wave Propagation in the Western Baltic Sea

Kurzfassung

This study investigates the influence of sea water salinity variation on the ground-wave propagation delay of Medium Frequency Ranging Mode (MF R-Mode) signals in the western Baltic Sea. A theoretical sensitivity analysis demon- strates how variations in salinity, common in regions such as the Baltic Sea, can significantly affect signal propagation. Using salinity data, we model and quantify the resulting differences in ground-wave propagation delay from the Hammerodde transmitter. Our results show that salinity-driven variation can induce phase delay differences corresponding to a ranging error of approximately 7 meters—highlighting the necessity of accounting for salinity in R-Mode system correction.