Double model created in DroneDeploy

Data Processing - Discussion and Q&A
1

Hi,
I am using DJI MAVIC 3T. I used manual flight mission mode and captured images covering whole under construction site. Image quality and no. of images are fine. But after I upload all the images for 3D Photogrammetry in DroneDeploy then I see double model instead of one model.
Your solutions will be really helpful.

2

Can you post any screenshots?

4

Were you using RTK? I have seen this happen when RTK is lost at some point during the flight. It could happen with standard GPS too but those images have higher accuracy values and the processing would probably bypass the problem. With RTK the machine assumes the drone is more correct and will actually model the additional surface.

6

10-4, I’ll take a look if you PM me the link. I am just interested to see the geotags between the individual images that captured that area. If one line had good GPS and the next line had issues then I think that would be a good clue as to what happened. If you can also provide a link to the map and I can see the calculated camera positions to make sure they match.

7

Hi Michael,

Which email address I can share the One drive folder where Images are stored?

Thanks & Warm regards
Dev
Contact No: (+65)-93849586

8

Left it in your DM’s.

9

@dev_omniwish Good morning. I have looked at the images and what I see is that you probably have a couple of things going on that would attribute to a break in the model.

  1. Is the vast amount of horizon in the images at the top of the stadium combined with the very low close-ups. The large differences in distance and elevation between what is close enough in horizon to pull points from and the close-ups is very hard for the photogrammetry to reconstruct. Exacerbated by the fact that your low images do not have a lot in common.

  2. You did a radial scan instead of tiles and your overlap is MAYBE 50% but the highly oblique angles have no real features in common. When modeling structures always try to keep the drone facing the surface. The exception would be if you are trying to get in an area where perpendicular facing just isn’t possible but you need the detail.

  3. Being in such close proximity of the structure and half the sky being blocked the GPS probably failed a couple of times on the lower shots but the share didn’t have a way to download so without being able to review a wide sampling I can’t say for sure if there were any major deltas in the geotags. At the end of the day this can be accounted for but I am not sure a machine can do it on it’s own so DroneDeploy support probably needs to put an eye on it to make sure all the images are aligning. If you can open the share to downloading and also upload the processing report i’ll take a look at that.