19/2020
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All COASTS OF ENGLAND AND WALES
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DISCONTINUATION OF GENERAL LIGHTHOUSE AUTHORITIES DIFFERENTIAL GLOBAL POSITIONING SYSTEM (DGPS) TRANSMISSIONS.
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Vessel owners, operators and masters are advised that, after careful consideration of the results of a comprehensive user consultation process, the General Lighthouse Authorities for the UK and Ireland have concluded that their Differential Global Positioning System (DGPS)is no longer required and have made the decision that the system will be discontinued from 31st March 2022.
The (DGPS) Service for UK and Ireland was established at a time when the publicly available GPS signal was intentionally degraded, resulting in large position errors. Augmentation was necessary to correct for these errors and meet minimum requirements for maritime positioning and navigation. In the year 2000, the intentional error in GPS positioning was removed. Since then, system technology has
improved and the GPS constellation has been modernised. Observed positional accuracy for unaugmented GPS now consistently meets IMO requirements for accuracy around the coast of the UK and Ireland for marine navigation.
How will the discontinuation impact you?
For the vast majority of maritime users, the discontinuation of DGPS service for the UK and Ireland will not impact the accuracy of satellite positioning. DGPS receivers will no longer receive the DGPS signal in areas where it was previously available. This may generate a ‘lost signal’ alarm, but receivers will still provide a GPS derived position.
Alternate sources for high accuracy positioning
Other options are available for obtaining higher accuracy positioning in the UK and Ireland.
Further Navigation Warnings will be issued when the above changes take place.
By Order,
Commander N. Hare,
Director of Navigational Requirements.
Trinity House,
Tower Hill,
London,
EC3N 4DH
28th September, 2020.