Traditionally, mariners would use physical AtoN and compass bearings to traverse our waters. Whilst those methods remain critical to safe navigation, most vessels today navigate using Global Navigation Satellite Systems (GNSS) such as GPS. GNSS provides an estimate of the receiver’s position and time, which the mariner can use to support safe navigation. In addition, GNSS is used within some of our AtoN infrastructure to provide their reported position and to synchronise communications.

It is widely understood that GNSS is vulnerable to interference, which can lead to a loss of capability or significant error in the reported position. When satellite signals fail, mariners and our AtoN systems need to maintain operations and therefore require dependable alternatives.

GRAD is researching systems and techniques which help a mariners detect when GNSS is unreliable and supporting the development of credible complementary PNT systems to GNSS.  We are working with national and international partners (IALA, IMO etc.) to support the development of, and the standardisation of, resilient PNT across the maritime domain.

GRAD maintains a radionavigation laboratory which allows us to receive many different PNT signals and test different services.  We conduct trials of systems in the laboratory and on-board the GLA fleet of buoy tenders. These facilities offer fantastic opportunities to test new systems in real-life, operational, scenarios.