As the snow began to melt a couple of weeks ago Crucial Services undertook a photogrammetry and mobile laser scanning survey of Chirk Aqueduct, the adjacent Viaduct, the canal tunnel passing under the railway and the local roads above both.
The photogrammetric survey was undertaken early Sunday morning before any passenger or freight train traffic was running on the line and before crowds of people were using the canal. Over 2,800 photographs were taken of the area – split into batches to ensure visual line of sight (VLOS) was maintained at all times.
3D model of Chirk aqueduct and viaduct
20 million triangle Model with 4.84 gigapixel textured mesh
Click to open the interactive model
Subsequently, a mobile 3d laser scan was measured of the same areas. Again split into loops to keep within the optimal scan duration. Additionally, a loop was measured through and over the canal tunnel. This was carried out using a GeoSlam Horizon RT Vision in a handheld configuration.
This image shows the mobile laser scan data of Chirk Aqueduct, floodplain, tunnel and Station Rd
Mobile laser scan data overlain
upon the photogrammetry orthophotograph
Photogrammetry Orthophotograph of Chirk Aqueduct
Topographical data with orthographic image
End to end the survey took 3 hours including:
- Time for site reconnaissance;
- Preparing the ground control points for the photogrammetry and the mobile lidar scan;
- Preparing for the drone operation with pre-flight and post-flight checks and individual flights missions;
- Switching from the drone equipment to the GeoSLam equipment;
- Measuring the 5 mobile lidar scan loops to cover the tunnel, floodplain, Station Road and around the North and South tunnel entrances.
Point Cloud data from the photogrammetry survey with the tunnel lidar laser scan survey data (red)
If you would like to talk about how we can survey your assets or sites, from both the ground and the air, for the most comprehensive survey possible please contact us