office of public works (opw) are the state agency in ireland tasked with management
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DESCRIPTIONIrish mapping agencies. Office of Public Works (OPW) are the state agency in Ireland tasked with management of physical Irish coast line and coastal defences (20 -30 staff). Ordnance Survey Ireland (OSi) are the semi-state agency in Ireland tasked with - PowerPoint PPT Presentation
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 DTMsInclusion of high resolution coastal DTMs
The coastal DTM will extend up to at least Highest Astronomical Tide -to 12nm offshoreE.g. Bantry Dunmanus
Bantry & Dunmanus Bay Co Cork (2006)
Water column penetrating Marine LIDARVessel 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
Water column penetrating Marine LIDAR Surveys in Ireland2002 - Clew Bay Initial trial for the Geological Survey of Ireland (GSI)
2003 - Clew Bay - Completion of the Clew Bay Survey for GSI2003 - Survey of part of Killala Bay for GSI / Moy Valley Company2005 - Mulroy Bay survey for GSI / County Donegal.2006 Bantry Bay, Dunmanus Bay, South Galway Bay
Satellite mapping!PROTEUS Ltd
Map of Wexford Harbour derived from satellite Imagery. 0-10m
Useful overview but not accurate enough (2m x 2m) for shipping safety2012 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 acquisitionVessel acquisition versus Satellite acquisition in the Shannon Estuary2013 campaign of 5 bays acquisition
LIDARLIDAROffice of Public Works (OPW) Topographic coastal LIDAR Surveys in IrelandThe 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 IrelandOPW Coastal Topo Lidar coverage
TopographicLIDARpotential forcoastal Ireland
Topographic onshore LIDAR Surveys in Ireland flown by OSiAll 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 approach
Medium water vessels 14,000 per day
Medium to shallow vessels 7000 per day
Shallow water vessels 3000 per dayMarine LIDAR costs:
Survey mobilisation 250k
Per bay cost --- complex 500k least complex 100kSatellite costs:
Survey mobilisation 50% of contract price
Per bay cost --- complex 50k least complex 20kTopographic LIDAR costs:
Survey mobilisation 25k - 50k
Per bay cost --- complex 100k least complex 20k