There are 2 main possibilities to map pole and / or tower structures:
A very high overlap is required (more than 90%).
If the structure is not fully reconstructed in the rayCloud, it is possible to digitize it by creating polylines and by refining the vertices of the polylines in the images.
Using a fisheye camera may help to capture the images because of the wide field of view of the lens.
It is recommended to fly close to the structure and as flight plan, there are several possibilities:
- Turning several times around it while changing the altitude, following a spiral.
- Making several circles around the object at different altitudes.
- Making several vertical length from the bottom to the top of the structure, at different positions around the object.
In all cases, it is needed to have a very good overlap between images (at least 85% frontal and side overlap).
The camera should have a 45 degree angle pointing to the ground. By pointing the camera to the ground, less sky content is visible on images which make them easier to match and it provides a better model. For more information: