Clustered cameras and missing parts of reconstruction

[Tectea]

We have some problems processing a dataset captured over a forest. The overlap is 75%, 65% but in some areas in the forest the altitude is increasing a bit which would decrease the overlap. We were trying to take off from the highest-ish point. Processed through Lightning Network with ish-forest standard settings.

Some areas are not being reconstructed and the assumed camera locations get clustered which can be seen in the image. Any ideas on how to handle this? Have tried a couple of settings without success.

Thank you in advance!
/Magnus Blomberg

[Saijin_Naib]

Welcome! The overlap and sidelap are likely just too low for such a homogeneous scene, hence the gaps and clustering of calibrated camera positions.

You can try:
–feature-quality high (ultra if processing locally)
–matcher-neighbors 32
–min-num-features 128000

[uplanddog]

Does your flight planner have the ability to adjust waypoint altitude per online elevation? this way to keep your elevation consistent helping overlap and GSD remain constant.

[Tectea]

Thank you for your answers!

I have tried increasing --matcher-neighbors to 24 and --min-num-features to 64000 but I can try your suggested values.

I’m using DroneDeploy which has the ability to set altitude based on elevation. The area was too big for them to support it though and I have already used two full days to collect the data (~1000 ha). So hopefully there is some way to fix the missing parts without flying again.

Is there any benefit to dividing it into smaller areas?

Should I use --use-3dmesh ?

[Gordon]

@Tectea

I’m using DroneDeploy which has the ability to set altitude based on elevation

It does, but only if using iphone, at least that’s how it was 12 months ago when I last used DD, with an Android phone.

[Tectea]

I’ve tried with 32 and 128000 but without any improvements on that part of the map. Any further ideas?

I’m trying to divide the datasets to see if I can get some information from the missing parts.

[Saijin_Naib]

Are you able to post the full dataset somewhere like our DroneDb.app so we can get a better look at it?

[Tectea]

@Saijin Please see email with link to dataset.