Navigating around a golf course is not something one should need a lighthouse for, particularly if the beam comes from somewhere remote like Mizen Head or Tory island. However, a new system for improving safety at sea is to have direct application on dry land from today.
Not just skippers, but also ambulance drivers, fire fighters, hauliers and - yes - golf links' designers will all benefit from the new satellite navigation system which is due to be transmitted through three lighthouse stations from this morning. The unencrypted Differential Global Positioning System (DGPS) is being introduced by the Commissioners of Irish Lights (CIL), as part of a programme involving the General Lighthouse Authorities of Britain and the Republic.
Differential GPS is an improved version of the standard GPS system of satellite navigation, which was designed by the US military and now has widespread civilian application. The improvements are reflected in accuracy and in quality control, according to Lieut Gary Delaney of Charternav, who recently left the Naval Service to set up his own GPS consultancy in Carrigaline, Co Cork.
Whereas standard GPS has an accuracy of plus or minus 100 metres, DGPS claims one to five metres. The fact that the signal will be transmitted through three lighthouse stations also introduces an element of quality control, in ensuring that broadcasts can be checked and corrected. "The service is free, and all one needs is a differential receiver," he says, which can be purchased for £1,500 to £2,000.
The three lighthouses - at Mizen Head, Co Cork, Loop Head, Co Clare and Tory island, Co Donegal - will begin transmitting on a trial basis from today, until the service is up and running on June 30th. Mariners have been advised by Irish Lights there may be occasions in the early stages when the service will be switched off for periods of up to 24 hours, and the existing radio direction finding (RDF) service from these lighthouses may also be interrupted. However, such details will be issued as part of routine navigational warnings by the coast radio stations.
The US company Trimble has won the contract from the General Lighthouse Authority to provide the hardware and software for DGPS. It has been signed up to establish 12 DGPS stations and three control centres around Britain and the Republic, providing the first continuous DGPS service on these islands.
DGPS is already on-line in much of Europe, the US, and Canada and the beauty of the system is that it has both land and sea application, Lieut Delaney says. Being non-directional, it can be picked up inland - in rivers, estuaries, lakes, on roads, in fields. Haulage companies which already use GPS for tracking their trucks will be able to benefit, and it has a security dimension for delivery of "sensitive" cargoes.
Mapping will be facilitated by free movement. "Equipped with the receiver, one will be able to walk, drive a car, steam a ship and get real time information," he says. The golf course designer will be able to walk along the edge of the fairway, instead of taking endless readings in fixed positions. "It closes the gap between surveying and ordinary navigation. The one rider is that it still depends on the GPS signal, and if that goes down so does the system."
All good mariners never rely on one system in any case, he notes. Due to the discontinuation of the terrestrial Decca Navigator System, its replacement, Loran-C, will provide the necessary back-up - if the Loop Head mast row can be resolved.
Significantly, there is one "glitch" in the DGPS coverage. There is a "black hole" in north Tipperary - by pure coincidence, the constituency of the current Minister for Defence.
