NTA Walking and Cycling Project

Scope

The survey was commisioned by Dublin City Council to provide detailed information as part of the NTA Walking and Cycling Plan to allow the design and construction of a number of cycle routes to be constructed throughout the greater Dublin area.

To facilitate this work, a detailed topographical survey, drone survey and permanent control network was required along a number of routes.

Lot 4 and Lot 5 routes covered a total approximate area of 1.5 million m2 of urban and suburban environments.

Topographic Survey

• All topographic survey features surveyed using ground based laser scanning and Total Station techniques.

• The survey covered approximately 236m length of LUAS Red Line and 27m of LUAS Green line which required coordination with relevant stakeholders.

• kerbs, different types of paving, carriageway surfacing, concrete flags, brick paving, antique granite, concrete, steps, etc surveyed.

• Roof lights, private landings, cellar covers, utility covers and the location of building rainwater downpipes surveyed.

• Levels at 10m intervals.

• Walls, railings, street furnishings, doorways or alcoves (including all details of recess) and steps at entrances surveyed.

• Road markings surveyed.

• Survey Control established using STATIC GNSS with stations levelled using digital level.

Drone Survey

• Drone flights carried out along the length of all of the project routes.

• 2cm Ground Sampling Distance along with Geo-referenced tiled .TIFF images provided.

• Drone data captured at a height above ground level at approx 40m, with a minimum of 80% overlap horizontally and laterally between the images.

• A combination of nadir and oblique images were captured to allow a 3D model or point cloud to be extracted from the data by Dublin City Council.