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Photogrammetry is important as it can be used to create a Digital Surface Model (DSM), a 3D representation of the ground surface. Knowing the height of the Earth’s surface is important for a number of reasons.
DSM’s of coastal areas are useful to anyone working in the coastal zone. These include scientists, engineers and coastal managers. Knowing the shape of coastal sites is vital for understanding coastal processes such as flooding, wave action, water currents and sediment (e.g. sand) transport.
Coastal flooding happens when low-lying areas are covered by water. This happens when seawater is pushed onto the land (e.g. in a storm), or from river water escaping from the river and covering the land. DSMs allow low-lying areas at risk of flooding to be identified.
Waves hit against our coastlines. How this wave energy affects the coast depends on the shape of the coastline. Some places will receive the full energy of waves, while other places can reflect wave energy elsewhere. Identifying how waves hit against the shore help geoscientists to understand processes like erosion and deposition of sediment.
Currents flow in the sea. The shape of the coastline changes how these currents flow. DSMs allow marine and coastal scientists understand how water moves along the shore.
Erosion (rock or sediment being removed) and deposition (sediment being deposited) occur around the coast due to the processes of wave action and current flow. DSMs produced at different times (e.g. 5 years apart) can show difference in the shape of the ground. These changes in the ground level allow geoscientists to see where erosion and deposition is occurring. |
| summary:
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Photogrammetry is important as it can be used to create a Digital Surface Model (DSM), a 3D representation of the ground surface. Knowing the height of the Earth’s surface is important for a number of reasons.
DSM’s of coastal areas are useful to anyone working in the coastal zone. These include scientists, engineers and coastal managers. Knowing the shape of coastal sites is vital for understanding coastal processes such as flooding, wave action, water currents and sediment (e.g. sand) transport.
Coastal flooding happens when low-lying areas are covered by water. This happens when seawater is pushed onto the land (e.g. in a storm), or from river water escaping from the river and covering the land. DSMs allow low-lying areas at risk of flooding to be identified.
Waves hit against our coastlines. How this wave energy affects the coast depends on the shape of the coastline. Some places will receive the full energy of waves, while other places can reflect wave energy elsewhere. Identifying how waves hit against the shore help geoscientists to understand processes like erosion and deposition of sediment.
Currents flow in the sea. The shape of the coastline changes how these currents flow. DSMs allow marine and coastal scientists understand how water moves along the shore.
Erosion (rock or sediment being removed) and deposition (sediment being deposited) occur around the coast due to the processes of wave action and current flow. DSMs produced at different times (e.g. 5 years apart) can show difference in the shape of the ground. These changes in the ground level allow geoscientists to see where erosion and deposition is occurring. |
| accessInformation:
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Geological Survey Ireland |
| thumbnail:
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thumbnail/thumbnail.png |
| maxScale:
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72089.95218638098 |
| typeKeywords:
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["Data","Service","Image Service","ArcGIS Server"] |
| description:
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<DIV STYLE="text-align:Left;"><DIV><DIV><P STYLE="margin:0 0 14 0;"><SPAN><SPAN>Photogrammetry is a remote sensing technology, i.e. the technology is not in direct contact with what is being measured. From drone, aeroplane or helicopter, photographs are taken. Multiple overlapping photographs of the ground are taken. Precise measurements from the photographs can be taken to create topography maps.</SPAN></SPAN></P><P STYLE="margin:0 0 14 0;"><SPAN>This data was collected using a drone carrying a digital camera in 2020</SPAN><SPAN> and 2021.</SPAN></P><P STYLE="margin:0 0 14 0;"><SPAN><SPAN>A software package was used extract points (X,Y,Z (x & y coordinates) and z (height)) from the photographs. The data is then converted into gridded (GeoTIFF) data to create a Digital Surface Model of the earth.</SPAN></SPAN></P><P STYLE="margin:0 0 14 0;"><SPAN><SPAN>An ordnance datum (OD) is a vertical datum used as the basis for deriving heights on maps.</SPAN></SPAN><SPAN><SPAN> This data is referenced to the Malin Head Vertical Datum which is the mean sea level of the tide gauge at Malin Head, County Donegal. It was adopted as the national datum in 1970 from readings taken between 1960 and 1969 and all heights on national grid maps are measured above this datum. </SPAN></SPAN></P><P STYLE="margin:0 0 14 0;"><SPAN><SPAN>Digital Terrain Models (DTM) are bare earth models (no trees or buildings) of the Earth</SPAN></SPAN><SPAN><SPAN>’</SPAN></SPAN><SPAN><SPAN>s surface.</SPAN></SPAN></P><P STYLE="margin:0 0 14 0;"><SPAN><SPAN>Digital Surface Models (DSM) are earth models in its current state. For example, a DSM includes elevations from buildings, tree canopy, electrical power lines and other features.</SPAN></SPAN></P><P STYLE="margin:0 0 14 0;"><SPAN><SPAN>Hillshading is a method which gives a 3D appearance to the terrain. It shows the shape of hills and mountains using shading (levels of grey) on a map, by the use of graded shadows that would be cast by high ground if light was shining from a chosen direction.</SPAN></SPAN></P><P STYLE="margin:0 0 14 0;"><SPAN><SPAN>This data shows the hillshade of the DSM.</SPAN></SPAN></P><P STYLE="margin:0 0 14 0;"><SPAN>Th</SPAN><SPAN>e </SPAN><SPAN>Kilmichael Point</SPAN><SPAN> and Dalkey Island data was collected by the Geological Survey Ireland. </SPAN></P><P STYLE="margin:0 0 14 0;"><SPAN>Th</SPAN><SPAN>e </SPAN><SPAN>Bremore Head,</SPAN><SPAN> </SPAN><SPAN>Bunmahon</SPAN><SPAN>,</SPAN><SPAN> Dunbeg, Ferriters and </SPAN><SPAN>Illauntannig </SPAN><SPAN>data was collected by the CHERISH Project. The CHERISH project looks at coastal sites that are important to human history. These sites have important structures (for example buildings or burial sites) that may be impacted by changes to our coast. </SPAN></P><P STYLE="margin:0 0 14 0;"><SPAN>All data formats are provided as GeoTIFF rasters. </SPAN></P><P STYLE="margin:0 0 14 0;"><SPAN>Raster data is another name for gridded data. Raster data stores information in pixels (grid cells). Each raster grid makes up a matrix of cells (or pixels) organised into rows and columns. This data has a grid cell size of 0.25 meter by 0.25 meter. This means that each cell (pixel) represents an area of 0.25meters squared.</SPAN></P></DIV></DIV></DIV> |
| licenseInfo:
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<DIV STYLE="text-align:Left;"><DIV><DIV><P STYLE="margin:0 0 14 0;"><SPAN>This data was produced by Geological Survey Ireland (GSI) and is free for use under the conditions of Creative Commons Attribution 4.0 International license.</SPAN></P><P STYLE="margin:0 0 14 0;"><A href="https://creativecommons.org/licenses/by/4.0/" STYLE="text-decoration:underline;"><SPAN STYLE="text-decoration:underline;"><SPAN>https://creativecommons.org/licenses/by/4.0/</SPAN></SPAN></A></P><P STYLE="margin:0 0 14 0;"><A href="https://creativecommons.org/licenses/by/4.0/legalcode" STYLE="text-decoration:underline;"><SPAN STYLE="text-decoration:underline;"><SPAN>https://creativecommons.org/licenses/by/4.0/legalcode</SPAN></SPAN></A></P><P STYLE="margin:0 0 14 0;"><SPAN><SPAN>Under the CC-BY Licence, users must acknowledge the source of the Information in their product or application.</SPAN></SPAN></P><P STYLE="margin:0 0 14 0;"><SPAN>Please use this specific attribution statement: "</SPAN><SPAN STYLE="font-weight:bold;">Contains Irish Public Sector Data (Geological Survey Ireland) licensed under a Creative Commons Attribution 4.0 International (CC BY 4.0) licence</SPAN><SPAN>".</SPAN></P><P STYLE="margin:0 0 14 0;"><SPAN>In cases where it is not practical to use the statement users may include a URI or hyperlink to a resource that contains the required attribution statement.</SPAN></P></DIV></DIV></DIV> |
| catalogPath:
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|
| title:
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IE GSI Photogrammetry Digital Surface Model (DSM) Hillshade 25cm Ireland (ROI) ITM MH TIFF |
| type:
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Image Service |
| url:
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https://gsi.geodata.gov.ie/imagehost |
| tags:
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["Ireland","IE/GSI","LiDAR","Topographic","Elevation","Photogrammetry","Hillshade","DSM","Digital Surface Model","Malin Head Vertical Datum","Kilmichael Point","Dalkey Island","Bremore Head","Bunmahon","Dunbeg","Ferriters","Illauntannig","Dublin","Kerry","Waterford","Wexford","CHERISH"] |
| culture:
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en-US |
| name:
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IE_GSI_Photogrammetry_DSM_HS_GSI_25cm_IE26_ITM_MH_TIFF |
| guid:
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|
| minScale:
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1153439.2349820957 |
| spatialReference:
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IRENET95_Irish_Transverse_Mercator |