Photogrammetry

Photogrammetry for surveying and mapping an area, uses aerial photography along with powerful processing to ascertain measurements between objects, both horizontally and vertically. With GPS reference this allows detailed measurement of distances on the ground, areas, heights of objects, and the calculation of volumes. It allows the creation of geo-referenced maps, digital elevation and surface models, and 3D models.

Photogrammetry, as a science, has had a long history, and has used photographs taken from planes. The rise in drone technology has seen a rapid development of online and desktop software to utilise the detailed images taken from the usual working height of up to 120m. The lower the drone, the higher the resolution of the maps and models produced. Drones are ideal for Photogrammetry as they have precise GPS and can be controlled exactly to take overlapping images.

Below is a plan of an automated flight and the position of images taken vertically, with a circle taking slightly angled images.

Photogrammetry

The resulting 3D model is below.

Photogrammetry

This is a 3D view of the camera positions and view of a survey using vertical and oblique views.

Photogrammetry

Below is the actual flight plan and camera positions used to capture data over Foel Drygarn. The 3D model is below.

Photogrammetry Flight Plan

This is an example live 3D model of an Iron Age Hillfort in Wales. Note: the detail is not as good as the actual model due to compression on the sharing site.