OpenDroneMap with GCP

Hello,
I have run several times Opendronemap with gcp, i used this format:

geo_x geo_y geo_z im_x im_y image_name

As example here the first lines of the file (gcp_list.txt):
+proj=utm +zone=19 +south +ellps=WGS84 +datum=WGS84 +units=m +no_defs
337188.74 6214940.58 497.694 3106 1056 100_0009_0139.JPG
337188.74 6214940.58 497.694 3046 1685 100_0009_0140.JPG
337188.74 6214940.58 497.694 2981 2307 100_0009_0141.JPG
337188.74 6214940.58 497.694 2918 2914 100_0009_0142.JPG
337188.74 6214940.58 497.694 3880 1717 100_0008_0351.JPG

After running the program the surface im getting is wrong because is a river and it should be going down in altitude but what happens its starts up goes down and goes up again. As example should be 10 5 0 and is 10 5 10. What could i been doing wrong? the textures seems to be ok the problem is with the altitude.

Hmm, the most likely candidate is the use of a camera with a rolling shutter.

I assume you are seeing a doming or bowling effect in the data? If so, what is your camera and what platform are you flying?

2 Likes

Hi thanks for the quick response,
the photos were taken with a Drone (Phantom 4 rtk) and the program used was Pix4Dcapture

sorry if my english is a bit rusty, haven’t practised in a while

Hi thanks for the quick response,
the photos were taken with a Drone (Phantom 4 rtk) and the program used was Pix4Dcapture

Hmm, I think the phantom 4 has a global shutter.

How is the elevation model shaped when run without the GCPs?

I have done many without gcp but with other drone and drone deploy. I will run this one without gcp and i tell you what comes out. What do you think may be happennig?

It’s unusual for there to be doming or bowling in any global shutter datasets. It’s not impossible, but unlikely. But, GCPs could introduce some issues: it could be an issue with the GCPs themselves, or perhaps we have an issue with how we are handling GCPs.

If it’s run without GCPs and we don’t see doming/bowling, then we know the issue is somewhere in the introduction of GCPs and we can troubleshoot from there.

If you need pictures or any other info i can send it to you via Google Drive or similar.

I’d be interested to know what settings/config others are using for Phantom 4 RTK for the most accurate results/etc

I’ve determined good workflows on Pix4D and have been working on trying to figure out best workflows for Metashape Pro… and now just need to figure out the best workflow/settings for ODM so definitely interested to learn what others are doing.

Good questions, @techris – can you open a separate thread? It’s best to keep the threads separate for related but related info. Otherwise, your question will get buried in another conversation (or vice versa).

More than likely, we’ll want to see the data shared via google drive or similar. :smiley: But run it without GCPs first and we’ll escalate from there.