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Need to improve my results and understand the outputs I am getting

Hi there,

Would someone be willing to help me improve my results that I am getting? I have just done a new mission of about 100 acres and I am trying to understand the results I am getting and how to improve them.

Here is the mission and the parameters that were used:

 

Where I look at the results on Map Easy everything looks great:

https://www.mapsmadeeasy.com/maps/public/ee51033e0ea74c0aa55f2ff70b7f5630/ 

However when I download the images created there are sections missing:

 

 

All the images seem to be square.

There is a file with "patch" in it's name that seems to contain the missing areas but at a lower resolution. Not sure if I am meant to patch together the full image?

Then the overlap report seems to be pretty bad, especially where the missing parts are. Not sure why parts of the overlaps are good and other bad. I would understand if the edges were bad but then I would expect consistency in the middle section.

Can this map be recovered? and how can I do better next time?

Thanks for taking the time to read my post. Feel free to ask any questions.

Thanks

Tony

Tony Juays

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The areas are missing because of a lack of overlap in treed areas. This is covered in the Data Collection guidelines that are agreed to at the time of upload:

Use LOTS of Overlap in Treed or Crop Areas

Trees are hard to render because they are typically almost always in motion and have a lot of fine detail.

Generally, the orthophoto portion of the processing may turn out fine at 65-70% overlap. However, if there are trees included in survey area and you want the 3D components of the processing to turn out well, we recommend using 80-90% overlap in order to make sure we have enough information to represent the trees properly. Bare trees are extremely hard to reconstruct well due to the complexity of the branches and shadows. Extra overlap should be used but even then it can be difficult. Also, avoid windy days when trees are involved.

For the partial outputs these two links have a full explanation:

https://support.dronesmadeeasy.com/hc/en-us/articles/360054457952-Flat-Map-Failover

https://support.dronesmadeeasy.com/hc/en-us/articles/360054461812-Flat-Maps

tl;dr - The areas that were not covered well enough to reconstruct were filled in with the Flat Map system. The output of the system is available in the Flat Map Patch geotiff file. 

Zane
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Also, looking at your Patch file it became pretty obvious that the reason those images were not included was because of the super strong sun spot due to taking the images too close to solar noon. 

Mixing lightings and times of day for data collection will hurt the ability of the system to match features. 

Zane 0 votes
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Thanks Zane for the response. I am only trying to understand the system better in order to get better results, not criticize Maps Made Easy. 
Would you split this into several missions but upload the files as one map? Or just fly the whole mission with a 90% overlap?

 

Tony Juays 0 votes
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Also the mission was started at 3:45pm and finished at 6:11pm.
Solar noon in my area is 1:26pm. The mapping was started left to right just FYI.

Tony Juays 0 votes
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The real solar noon guidance is to make sure the aircraft's shadow does not fall within the field of view of the camera. You can see that in the images in the southeast of the map the sun spot was SUPER strong (see image). So for wider FOV cameras like the P4 the number might be more like 3 hours. Or shoot on overcast days. 

80% overlap is fine. It also looks like you had issues maintaining the RC connection which lead to that eastern portion falling apart. 

82% overlap and no sunspots will turn out fine. 

Zane 0 votes
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Maybe there was an issue with the timezones or something but it looked like your data was collected earlier. 

Zane 0 votes
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Perfect!
Thanks for that feedback.

I did not realize that connectivity to the RC was required. I thought once the mission was uploaded to the drone it flew autonomously! I will make sure to maintain RC connectivity in the future.

Thanks again

Tony Juays 0 votes
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