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Mavic Processing with GCP Workflow

Hey guys, I know there has been a lot of issues regarding the Mavic/Mavic 2 with processing but I just wanted to share our workflow that is currently working for us. Also I would love to hear what anyone else is doing to see if we can help tighten/speed up our processing:

  1. Import images
  2. Import GCP
  3. Go to the Process menu at the top of the app and then go down to Processing Options
  4. Make sure Advanced is turned on in the lower left and navigate to the 1. Initial Processing on the left
  5. Under the Calibration tab go down to Calibration and change the Internal Parameters Optimization from “All” to “Leading” then press OK to save.
  6. Run step 1 only, Initial Processing
  7. After processing you might get what we like to call the “little big planet” effect where the point cloud has a curve to it like a tiny globe. To reduce/eliminate this curve create MTP all over the project, we like to pick a few on all edges of our work space to help flatten things out nicely.
  8. After creating the MTP run Re-optimize to see how well the curve has been reduced and now tie your GCP to your markers on your cloud.

I hope this helps someone out. We have been running into countless issues with the Mavic’s in the processing stages over the last few months and it looks like this process has finally started to make our lives easier. 

Hello Jason,

Thank for sharing your experiences. It is highly appreciated.

Have you tried to add/mark the GCPs before the MTPs? I think that would help to reduce the curve too.

Thank you very much.

 

Yes we have and it does not seem to fix the curve in the sites at all. A lot of this has to do with the types of flights we are doing, very long and narrow, so I’m sure it will work with other workflows.

Hello again,

What is happening to you is probably related to what it is explained in this article: Corridor project errors

It is a problem which can happen with any drone and not particularly with the Mavic 2, especially when there are not at least two strips or the GCP distribution is not the best. Corridor project are always more complicated as they are narrow and long.

There are also some other articles in our knowledge base which might help you:

Regards.

 

 

Yes, we have seen and read the articles and have told our engineers numerous times to try and go as wide as possible so we can fix some of these issues. Unfortunately a lot of the time we are racing to get jobs done before the sun sets, or other natural obstructions. Additionally we cannot revisit the site later as its always remote work and has to be done immediately so we work with what we can back here in the media department. Although the issue still occurs with our other drones, mostly Phantom 4 Pros, the effects are dramatically enhanced when the Mavic is used. Also up until recently we couldn’t even get the GCP to work with the drone images in Pix4D, we had to align the points to the ortho in CAD manually after we processed the photos with no GSP data.

Hello Jason,

I am not sure what is the reason for not being able to use the GCPs.

I suppose it has to do with a shift in the height value.

If that is the case, please have a look at this article where that problem is explained and there are some proposed solutions:Vertical shift between the model and the GCPs so no GCPs can be marked

Regards.