Any UAS gurus out there?
We've been doing some route surveys in forested areas and are having a lot of problems with the photos registering. Any tips and tricks for improving these results? More overlap? Fly higher? Fly lower? Any suggestions are appreciated.
I should add that we do the majority of the processing in Pix4D.
I'd suggest you supplement with higher flights near your ceiling. The greater distance between you and the tree tops, the easier time it's going to have matching the photos.
You left out a lot of variables.
A few questions:What are your side and front overlap?
- What is your AGL?
- How many flight lines are on your route?
- Are you using Terrain awareness?
- Are these trees conifers?
- Are the trees deciduous, what season? Are the leaves on or off?
- Is your camera NADIR or oblique?
- Are you using mapping grade GPS w/ GCP's, how many?
- Are you using RTK or PPK?
- What drone, sensor, and camera?
- Are looking for just an ortho-mosaic, or trying to calc 3d and elevations?
Mapping a route with a drone, I find you need at least 4 flight lines. Mapping deciduous treed areas are best down in the winter with only a few inches of snow cover. Pix4d will map through the trees down the ground survey. Mapping through conifers is almost impossible. Creating just the ortho-mosaic at too low AGL, may create camera mis-matching, if you don't have PPK or RTK and a good sensor.
Oh...I would like to see how this pans out...I've had the same issues.
Summer aerial from Google
Winter aerial from Pix4d