Gently Curved, Convergent, Non-traditional Drone Flight Paths

[Jim Dow]

Several questions have been posted regarding how to fly curved paths.
Check out the Amazon eBook entitled “Gently Curved, Convergent, Non-traditional Drone Flight Paths” for instructions about how to plan the mission.

 

[Jim Dow]

Minimising systematic error surfaces in digital elevation models using oblique convergent imagery
Rene Wackrow

Jim H. Chandler
First published: 16 March 2011

https://doi.org/10.1111/j.1477-9730.2011.00623.x

Results of the simulation process, the laboratory test and the practical test are reported in this paper and demonstrate that an oblique convergent image configuration eradicates the systematic error surfaces which result from inaccurate lens distortion parameters. This approach is significant because by removing the need for an accurate lens model it effectively improves the accuracies of digital surface representations derived using consumer‐grade digital cameras. Carefully selected image configurations could therefore provide new opportunities for improving the quality of photogrammetrically acquired data.

I hope this helps. Compare the images below: Traditional (linear/parallel) and Non-traditional (non-linear/non-parallel)

Jim Dow

 

[Jim Dow]

A convergent image configuration for DEM extraction that minimises the systematic effects caused by an inaccurate lens model
Rene Wackrow
Jim H. Chandler
First published: 27 March 2008
Results of the simulation process clearly demonstrate that a mildly convergent camera configuration eradicates the systematic error surfaces. This result was confirmed through practical tests and demonstrates that mildly convergent imagery effectively improves the accuracies of DEMs derived with this class of sensor.

This reference (above) prompted me to explore convergent, gently curved, non-traditional (non-linear/non-parallel) flight paths which did in fact help mitigate the systematic Structure-from-Motion doming/dishing (elevation) errors. I used a logrithmic-spiral formulation to construct the flight lines - see axamples. Google "Convergent, Gently Curved, Non-Traditional Drone Flight Paths" for the math.