A Measurement Based Accuracy Prediction Of Terrestrial Radio Navigation System For Maritime Backup In South Korea

This paper focuses on the Ranging Mode (R-Mode) for the backup solution which is considered as one of the measures to provide resilient PNT in global trend and also in Korea. R-Mode is the positioning and navigation system as Signals of OPportunity (SoOP), and is evaluated in terms of feasibility through the project of Accessibility for Shipping, Efficiency Advantages and Sustainability (ACCSEAS) project in Europe. Application of R-Mode has a strong point in the aspect of technology advantages and economic effect because existing radio infrastructure can be reused. South Korea runs Nationwide Differential GNSS (NDGNSS) currently which is in operation as following an IALA MF beacon service guideline. Thus, this makes the infrastructure possible source of R-Mode. Therefore, we propose to utilize R-Mode with integration of eLoran, as a method of safe navigation service for maritime domain in South Korea and analyze its validity. The feasibility validation was based on simulation in terms of service coverage and accuracy. We approached this simulation with theoretical and practical aspects. To realize this approach, we referred to ITU document but also used SNR measurements of NDGNSS beacon signal collected from monitoring station to reflect actual environment variables together. Performance prediction results regarding to positioning accuracy are presented in comparison with the requirements for IMO's maritime backup navigation system.