Maritime Demonstration Testbed for Galileo

EADS Astrium Ltd is developing a Test Environment in which to perform demonstrations of Galileo performance and differentiators for the maritime community. These demonstrations will be done prior to the availability of the Galileo system, hence some form of replication or simulation of the Galileo signal is required. This includes a number of Transmit Stations mounted on existing structures (cranes/gantries, berths, buildings, hills.) at accurately known locations overlooking the demonstration zones (up to several tens of kilometres in extent). These continuously transmit replica Galileo signals. Another key component of the Test Environment is the single Monitoring and Control Station. This monitors each transmitter's signal, calculates clock corrections and provides each Transmit Station with the contents of its navigation messages, emulating the function of the real Galileo central control facility. It also controls and monitors the demonstration signal scenarios. This paper presents a short overview of the requirements for Maritime users. Emerging performance requirements for maritime applications with respect to accuracy, integrity and availability require more from a GNSS System than can be supplied by GPS alone. In particular, identified applications in port areas (for example automated docking) and in inland waterways, have very stringent performance requirements. Candidates that may meet these emerging requirements include combined use of GPS and Galileo, potentially augmented by local aids such as Differential and Integrity Augmentation Systems and/or Pseudolites. The paper describes in detail the Maritime Test Environment, including the critical Transmit Stations (a variation of pseudolite technology). The Transmit Stations generate and broadcast navigation signals based on those planned for use by the future Galileo System. Transmit Stations will be self-contained, with continuous satellite-like transmissions at constant source level, preset and maintained for the duration of any demonstration. Operations are coordinated by a remote Monitoring and Control Station via a communications link, so that groups of Transmitters can be synchronised and work together as a single, coherent system. The design places few restrictions on the location of their deployment, ensuring that demonstration planners have the freedom to create optimal signal environments for maritime demonstrations or indeed for demonstrations for other application sectors.