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Walnut Mountain Map

I sent in a flight mission for Walnut Mountain and the northwest half of the map came back correct but the southeast portion was not. So I sent a set of photos from the same flight mission, for processing, using only those photos from the southeast portion of the flight and this time the southeast portion of the flight area was correct. The flight was made at an altitude of 100 meters with 387 photos taken. Why would this happen? The Overlap was 70/80 and in mountainous terrain.

Dennis Pierce

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The Data Collection guidelines say to use at least 80% when trees are involved, so 80/70 isn't quite there. Bare trees are even harder to deal with due to the complexity and hard shadows. That middle portion where it falls apart is all bare trees.

When you ran the second map with just the southern portion it had the grassy areas to hold on to and keep things together. You can see that it started to fall apart up towards the north again though.  

Bare trees can require 82-83% overlap to work well but even then it is going to be really lighting dependent for large areas like that. 

We will grant a one-time 50% refund for overlap related issues. 

Zane
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Thank You, 

I'm going to fly again and increase the overlap. If I fly a lower altitude will that also help? I realize the lower altitude and increased overlap will increase the flight time and I'm limited to to 60-70 minutes. Do you have a suggestion for the best combination of overlap and altitude to use for this mission?

Thanks again, I'm just learning 

Dennis Pierce 0 votes
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Flying lower would be harder, require more time and likely need a bit of extra overlap. With bare trees it helps to fly as high as you can to mitigate a bit of the complexity of the branches. 

Zane 0 votes
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