Analysis on the performance degradations of maritime DGPS reference station by radio environment

Abstract

The maritime differential GPS (DGPS), which broadcasts GPS pseudorange corrections via medium frequency beacon signal to improve position accuracy and reliability, is a ground-based augmentation system as well as one of the most-used augmentation systems in maritime applications. Now maritime DGPS reference stations are established in South Korea for improvement of GPS navigation accuracy and needs of integrity. This paper investigates visibility and interference environmentfor performance degradation of some DGPS reference stations. We find that in case of some reference stations, visibility is satisfied with 7 degree elevation angle, but interference environment is not satisfied with reference standard of -50dBm. In order to analyze the effect of interference environment, this paper proposes a time differential measurement analysis method excluding error of signal noise. Finally, in this paper, it is shown that measurement analysis result of reference station under interference environment is three times the error than that of reference station on normal conditions.