Referencing tide data to a known datum allows the geophysical data collected offshore to be tied into this datum. Control points are established at the tide gauge site using Leica RTK GPS equipment. A series of measurements and calculations are made that allow the height of the tide to be referenced to this point. The geophysical data is then referenced to the following datum;
Malin Head Ordnance Datum
Geoid or Mean Sea-Level
Lowest Astronomical Tide
The Malin Head datum is used as the fundamental reference point for all surveying work in Ireland. The Geoid is an equipotential surface that approximates the mean level of the sea. The Lowest Astronomical Tide or LAT is the lowest possible tide that can be experienced at a location under ‘normal’ meteorological conditions.
|Geological Survey of Ireland
Beggars Bush, Haddington Road
|Marine Institute Headquarters,