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