A Measurement Based Accuracy Prediction of Terrestrial Radio Navigation System for Maritime Backup in South Korea

Abstract

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. Horizontal position accuracy was predicted using Horizontal Dilution of Precision (HDOP) and User Equivalent Range Error (UERE) values. The HDOP is determined by the calculation of the fixed location information of transmitting station and changing location of the user. The UERE is an important parameter for determining accuracy performance prediction. 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 and Loran signal collected from research vessel to reflect actual environment variables together. HDOP analysis for R-Mode shows that there are some shadow regions in Korean waters not covered, as applying only NDGNSS MF beacon stations. On the other hand, if the existing Loran infrastructure is utilized as a combination, it can provide the safe navigation service to mariners as a maritime backup navigation system without GNSS in most of South Korea region. Performance prediction results regarding to positioning accuracy are presented in comparison with the requirements for IMO·s maritime backup navigation system.