Make sure to have the right overlap
In order to be certain the mapping will work, make sure to have at least an 80% in-track overlap and a 65% cross-track overlap.
Regarding the hight, the overlap should be adapted :
Don’t fly too fast
Take care of your flying speed, if you fly too fast this could lead to a low in-track overlap or worse, blurred pictures due to the excessive speed.
The higher you fly, the better your mapping will be. Try to fly at the maximum altitude you can, but remember to pay attention to local drone regulations, the ground resolution you need as well as potential obstacles.
Avoid big homogeneous areas
A large homogeneous area will not have enough marker points ; if you don’t take any marked and perceptible details (for instance roads or constructions at the edge of your fields) the mapping is more likely to fail.
Try to get mark points
The mapping software will be helped by precise and recognizable points. For example, if a road, car or house is close to the field you are working on, try to include this detail into your dataset in order to facilitate the mapping.
Avoid moving objects
If an object has moved between two pictures, it will be very difficult to generate the maps. Indeed, objects are used as marker points, so if they’re not at the same place on two different pictures the mapping software won’t be able to locate the pictures correctly. This problem could also happen in the case of moving vegetation due to strong winds.
Try to take nadir pictures
Try to take pictures as near to vertical as possible. At least avoid taking pictures with the horizon line visible.
Check your pictures on the field
Checking your pictures directly on the field is easy. If you look at the pictures one by one, you’ll be able to check the overlap (for a 80% overlap, a mark point should be visible on 5 successive pictures) and make sure texture and sharpness are good (pictures should be clear, well contrasted and well textured).