Differential GPS, which is the representative augmentation method for maritime navigation, has been widely used to enhance GPS positioning performance due to its minimal burden on transmitting the correction data and the ease of correction processing to improve position accuracy. The maritime differential GPS, which broadcasts GPS pseudorange corrections via medium frequency beacon signal, is a ground-based augmentation system as well as one of the most-used augmentation systems in maritime applications. Recently as the various satellite navigation systems are becoming available such as GLONASS, BeiDou, Galileo, and QZSS, there is growing need to provide maritime DGNSS service and establish maritime DGNSS related standards. For this reason, this paper deals with effects of multi-constellation GNSS on maritime augmentation service. Firstly this paper introduces the structure and the operation process of the traditional maritime DGPS. And then, the differences are shown between maritime DGPS and DGNSS. Finally it is presented that these differences can affect various parts of maritime augmentation service, such as correction age. It is anticipated that these analysis results will be utilized as a base study for maritime augmentation service under multi-constellation GNSS.

Keywords: maritime augmentation, multi-constellation, DGNSS, correction age