Office of Public Works (OPW) are the state agency in Ireland tasked with managementof physical Irish coast line and coastal defences (20 -30 staff)
Ordnance Survey Ireland (OSi) are the semi-state agency in Ireland tasked with management of onshore topographic mapping (140 -170 staff)
Geological Survey Ireland (GSi) are the state agency in Ireland tasked with mapping of onshore/offshore geological mapping (50 -80 staff)
Irish mapping agencies
Phase 2 – Coastal DTM’s
•Inclusion of high resolution coastal DTM’s
•The coastal DTM will extend up to at least Highest Astronomical Tide -to 12nm offshoreE.g. Bantry Dunmanus
Bantry & Dunmanus BayCo Cork (2006)
Water column penetrating Marine LIDAR
Vessel bathymetry
Drawbacks of Marine LIDAR usage:
- Turbidity (clarity of water)
- Contact resolution (1m x 1m dot density ideal)
- Cost (generally a factor of 5 increase as against onshore LIDAR)
- Increased post-processing capacity required
VERY TURBID WATERSHALLOW WATER
Water column penetrating Marine LIDAR Surveys in Ireland
2002 - Clew Bay – Initial trial for the Geological Survey of Ireland (GSI)
2003 - Clew Bay - Completion of the Clew Bay Survey for GSI
2003 - Survey of part of Killala Bay for GSI / Moy Valley Company
2005 - Mulroy Bay survey for GSI / County Donegal.
2006 – Bantry Bay, Dunmanus Bay, South Galway Bay
2008 - BLOM survey for GSI of Donegal/Sligo/Gretamans BaysTENIX survey of Tralee/Blacksod/Foyle Bays
2010 - Pelydryn survey for GSI of Inner Mulroy/Killala/Sligo/Lough Swilly/Galway Bays
Satellite bathymetry
Satellite mapping!
PROTEUS Ltd
WorldView-2 Satellite
Map of Wexford Harbour derived from satellite Imagery. 0-10m
Useful overview but not accurate enough (2m x 2m) for shipping safety
2012 test area in Wexford
Drawbacks of Satellite usage:
- Turbidity (clarity of water)
- Cloud (needs clear skies)
- Contact resolution (2m x 2m dot density ideal)
- Cost (generally a factor of 2 -3 increase on equivalent ship cost)- Increased post-processing capacity required
Proposed Irish baysfor satellite data acquisition
Vessel acquisition versus Satellite acquisition in the Shannon Estuary
2013 campaign of 5 bays acquisition
LIDAR LIDAR
Office of Public Works (OPW) Topographic coastal LIDAR Surveys in Ireland
- The best topographic coastal LIDAR flying dates are on the days of spring tide.
- The OPW LIDAR data flown in the coastal regions of Ireland are seeking coverage out to mid tide only.
- There are flown with the expressed end usage of managing coastal defences
Office of Public Works (OPW) Topographic coastal LIDAR Surveys in Ireland
OPW Coastal Topo Lidar coverage
TopographicLIDARpotential forcoastal Ireland
Topographic onshore LIDAR Surveys in Ireland flown by OSi
All Osi Topo Lidar flown to High Water Mark (HWM)
- The best terrestrial LIDAR flying dates are on the days of spring tide.
- Terrestrial LIDAR has no water penetration capability.
- The spring tide day usually occurs a day or two after both the full moon and then the new moon days of any calendar month.
- There are usually 2 spring tides in a calendar month.
- Flying to capture the low tide mark is only optimum for one (1) hour either side of the low water time on those spring tide days.
Topographic coastal LIDAR Surveys in Ireland flown by OSi
GSI Vessel bathymetry mapping!
Dublin Bay survey approachDublin Bay survey approach
Vessel costs:
Medium water vessels €14,000 per day
Medium to shallow vessels €7000 per day
Shallow water vessels €3000 per day
Marine LIDAR costs:
Survey mobilisation €250k
Per bay cost --- complex €500k least complex €100k
Satellite costs:
Survey mobilisation 50% of contract price
Per bay cost --- complex €50k least complex €20k
Topographic LIDAR costs:
Survey mobilisation €25k - €50k
Per bay cost --- complex €100k least complex €20k