What Flight Plans Are Good for Photogrammetry?

If you intend to collect drone data for creating a 3D model of a tower, there are some general best practices you might want to consider. Some of the general dos and don’ts include:

  • An overlap of at least 70% at the surface of interest.
  • If the ground station is part of the model, some images connecting the tower and the ground compound are necessary.
  • Keep the horizon and sky out of the images as much as possible (avoid
    negative/up-looking gimbals).
  • Fly on overcast day if possible.
  • Choose the right image resolution for the level of detail you want to achieve (In helix for example, determined by distance from tower and camera setup).
  • If you need extra detail around specific parts (like antennas, top part of tower), use a specific mission (like Antenna Orbits/Dome Orbits) to capture some extra images in these places.

In general, you might want to use a combination of two or three Drone Harmony patterns for best results. Here are some combinations that we know can work well.

Example 1

Helix (1x/2x)
Distance to tower: 5-8 meters
Overlaps: 75%
Gimbal angle: 0 deg + 30 deg
Dome Orbits
Radius: 5-8 meters
No of orbits: 4-8

Example 2

Verticals
Distance to tower: 5-8 meters
Overlaps: 75 %
Gimbal angle: 0 deg + 30 deg
Orbit
Radius: 5-8 meters

In case additional detail is needed around the antenna levels (e.g. is the antenna components need to have high detail in the model), you can additionally or alternatively use the following missions.

Antenna Orbits
1-3 orbits around each antenna level with up to
3 different gimbal angles
Compound Flights
Combinations of helix and orbit flights

In general, the exact type of mission that is suited for your needs might depend on the environment and the purpose of data acquisition. If, for example, the tower is hard to walk (circle) around, a “Verticals” mission might be better than a “Helix” mission, in case visual line of sight must always be kept with the drone.