Hello everyone again,
Thought I’d do a little survey to get a feeling for the reliably achievable GSDs people are getting from WebODM.
Might also help to have a few other parameters, such as flight altitude, drone used (or camera on the drone where its not the default one).
So for me:
GSD = 8cm, Altitude = 120m, Drone used = DJI Mini2 (12MP images)
I can get millimetres if I use my SLR on a pole.
Normally I aim for a GSD of 10mm with drones as it’s the most practical. That’s 36m AG with a Phantom 4 RTK.
According to the ODM Quality Report:
GSD=6.0cm, Altitude 400ft (122m), Mavic 2 Pro (20Mpx images), 2047 images, 354 acres (143 hectares)
10 hrs 54 mins to digest it all, default settings (fast ortho)
Winston it sounds like you are resizing images when you are creating your Tasks, as that should be roughly 4.33cm/px for 12MP at 400ft AGL, which is what I get from my 3DR Solo + GoPro Hero4 Black (12MP).
I’ve never had reason to fly closer as I was doing agricultural field survey exclusively, and a few cm GSD difference in data to make prescriptions on a variable rate implement that is 40m wide is 
Edit for clarity:
You can achieve any GSD you want with WebODM provided your input data and processing parameters are appropriate. And your machine has the resources (primarily RAM+swap/page) to do the maths.
Thanks guys.
Saijin, I’ve been leaving the resizing images as the default ‘yes’ 2048 pixels.
I’ve not experimented with turning this off yet, I guess Im expecting a much longer computational time if I do?
Potentially, or out of memory, depending on your machine, but it can absolutely be worth it.
That would be either resizing your images by 0.5X with ultra settings, or just using default high settings, as I get about 3cm from 120m with my M2P.
Non-georeferenced images mean I don’t see WebODM list a sensible GSD, but for some of the smaller items I make 3D images of with an SLR , the true “GSD” is <0.1mm.
Yes, I did resize them (I actually forgot that I did). I thought about rerunning it without a resize, but the customer was OK with everything as it was.
Ran some small plant seeds through an optical microscope and got (probably – don’t have the data anymore) 0.01mm GSD.
GSD is actually a combination of the reconstruction and the known points, first when the reconstruction gets the right scale you know the GSD or actually the effect of it.
DJI Phanton 4 Pro V2 with 20mp camera flying at :
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