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Processing completely wrong

My initial upload confirmation differs completely from the overlap report and the output is garbage - HELP!


Official comment


Yeah... That looks like crap. 


There are a few things going on here that are covered in the Data Collection guidelines that are agreed to at the time of upload. 

First, roofs are hard to do. They are among the hardest of things to do well. There are a few things you need to take into account to have them turn out well. They are normally featureless or have repeating patterns, both of which are hard to handle. In this case, the images were really bright in the middle and dark out towards the edges. This is likely due to the Mavic Pro's limited ability to capture dynamic range very well. As I am sure you can tell flipping through your images they almost all look the same.

Second, there were reflections on the solar panels which is something hard to deal with in general. You can mitigate the surface reflections by using a circular polarizing filter. 

Thirdly, and the most serious issue, the images on the roof really only have about 60% overlap. Assuming you took off from the ground and tried to take 76/80 overlap flying at 27 meters (per your log file), the overlap achieved at the top of that structure is far less. The ground gets what you set, but everything higher than that gets less. This is why we offer the Ground Offset feature which raises the plane for which the overlap is calculated up from ground level:

Lastly, it really helps to cover some of the areas that are surrounding the building to be sure to give the system enough to go on when figuring out what is ground and what is not. The top edge of this is a bit problematic. If you had included as much ground level coverage on the top and right as you did on the bottom it would likely have turned out better. 

With these factors it is no wonder the roof didn't turn out well. The first two are able to be dealt with better by the system if the second two are handled better by the pilot.

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


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