A Study on the Dissemination of Network-Based DGPS Corrections for e-Navigation

Abstract

E-Navigation is the harmonized collection, integration, exchange and presentation of maritime information onboard and ashore by electronic means to enhance berth to berth navigation and related services, for safety and security at sea and protection of the marine environment. At the 81st session of the International Maritime Organization (IMO) Maritime Safety Committee (MSC) in May 2006, the committee approved a new work item on e-Navigation. In order to meet the e-Navigation requirements, the following three fundamental elements must first be put in place: - a worldwide coverage of Electronic Navigational Charts (ENC); - a robust fail-safe electronic positioning system with redundancy; and - an agreed infrastructure of communication links between ships and shore.

Therefore this paper addresses the positioning system with redundancy and the communication links for maritime applications. The accuracy of GPS position solutions can be enhanced through the use of differential pseudorange corrections. Traditionally, differential GPS corrections are broadcast over a radio-link from reference station to user receiver. However, a variety of data links currently exit for the distribution of these corrections such as radio modem, maritime beacon, geostationary satellite and the Internet. The paper also focuses on the network requirement and performance analysis for dissemination of network-based DGPS corrections. It analyses the radio communication and wireless network system requirements, the dissemination method of DGPS corrections for e-Navigation, and the paper then presents the design, implementation and test result of network requirements.