Drone LiDAR

Case Study

UAV LiDAR and Photogrammetry Survey, Hayle, Cornwall

The Brief

Flythru were engaged to carry out a drone survey using photogrammetry and low-level LiDAR techniques of a large area of steep embankment between Clifton Terrace and King George V Memorial Way adjacent to the tidal estuary at Hayle, Cornwall.

LiDAR (light detection and ranging) was chosen to work alongside photogrammetry as a cost-effective technology creating a 3D model through dense vegetation on this site. An extracted Digital Terrain Model was required by Cormac Consulting to enable them to assess the ongoing landslide risk faced on the embankment which is covered in thick vegetation.

The Solution

FlyThru in collaboration  with our geospatial engineering partners Geoterra utilised a bespoke heavy lift drone equipped with a high definition DSLR camera and Routescene LiDAR system to fly over both the embankment and adjacent area using laser pulses to generate a large multipath multi-return laser scan point cloud. The point clouds were then post processed to produce an extracted vegetation ‘bare earth’ Digital Terrain Model. A DJI Phantom 4 Pro UAV was used equipped with a high definition camera  also to complete the photogrammetry survey of the same area flown with the UAV LiDAR. Ground control points were set up across the site and surveyed to OSGB OSTN 15 National Grid to facilitate future UAV LiDAR surveys to be carried out for monitoring purposes and production of isopachyte deformation models.Add blockAdd block

The Deliverables

Drone surveys provided the client with a with a range of key deliverables including a 3D Surface Model, Digital Elevation Model in LAS format, Ortho-rectified mosaic photography TIF overlay and extracted cross sections at regular intervals.