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Radionavigation - Resilient PNT


R&RNAV developed and deployed the world's first maritime eLoran service, which it ran as a testbed at Initial Operational Capability (IOC) until 31st December 2015. Work ceased and the system was decommissioned by the GLAs following the closure of 8 out of 9 Loran-C transmitters across northwest Europe. 

R&RNAV continue to maintain interest in the international developments of eLoran, the preferred option for Resilient PNT not only for maritime but cross sector; and using the expertise we have developed over the last 10 years we are able to continue to support the international community in their own eLoran developments.

The UK's transmitter at Anthorn in Cumbria is now operated by other Government Departments.  

The lack of international agreement on the selection of eLoran as the backup of choice has required the GLAs to invesitgate other options.

Our work in the field of Resilient PNT covers the analysis of the various options available to provide a complementary backup to GNSS, in particular GPS, the primary source of positioning and navigation information aboard ship.  

Options being investigated by R&RNAV include:

  • Radar Absolute Positioning - using radar to provide latitude, longitude and speed over ground directly
  • MF R-Mode - the addition of ranging signal components to IALA DGPS radiobeacon transmissions
  • Onboard independent navigation systems - the integration of Doppler speed log and gyrocompass (Dead Reckoning), or inertial navigation systems
  • Signals of Opportunity - using DAB and DVB-T signals in opportunistic navigation

In addition, the integration of various options is being investigated to provide hold-over in the event of the failure of GPS.

We perform our various radionavigation projects through a combination of our own technical work and external consultancy.

Technical work includes algorithm development, coverage prediction, and the perfomance of sea trials.