Differential Loran for Rotterdam
Dutch company Reelektronika has developed and successfully tested Enhanced Differential Loran (eDLoran) to back-up GNSS.
When piloting deep-draught vessels bound for Rotterdam - where the pilot boards about 35 miles off the coast - the Dutch Pilots' Corporation (Nederlands Loodswezen) currently makes use of a portable, autonomous navigation aid based on GNSS. By law, ships navigating the Eurogeul and Maasgeul shipping channels in the North Sea are required to carry an autonomous navigation system.
Satellite positioning is the basic element for the current navigational aid. But natural and intentional disruption of the satellite signal make satellite positioning vulnerable, and this vulnerability spurred Loodswezen to seek an alternative. Loodswezen and Reelektronika BV have consequently developed an alternative positioning system as a backup for satellite navigation. Reelektronika, led by Institute Fellow Prof Durk van Willigen, has for more than 15 years specialised in developing Loran equipment.
With financial help from the Harbour Master's Division of the Port of Rotterdam Authority, 2 years of intensive development and testing off the coast of Hook of Holland have resulted in a back-up electronic navigational aid - enhanced Differential Loran (eDLoran).
Totally independent of GNSS and working in a completely different part of the spectrum (100 kHz), eDLoran uses signals transmitted by towers in England, France and Germany. Based on these signals, a location can be determined with an accuracy of better than 5 metres, meeting the Government Port Approach Systems specification.
The test system that has been implemented includes an eDLoran reference station and eDLoran receivers for the pilots. These small, lightweight receivers can wirelessly interact with the standard software of the pilot’s GPS-RTK (real-time kinematic) equipment. Real-time differential Loran data is available via the mobile telephone network and no modifications to the existing eLoran transmitters are required.
Rotterdam is one of the busiest ports in the world, with about 32,000 ships visiting annually. To ensure safety and a smooth traffic flow, the vast majority of those vessels must have a pilot on board when entering and leaving the port.
Details from the links below . .