I am trying to pin down a best practice or some good answers to a question about 'consumer grade camera' and the phantom 4 rtk camera in typical aerial mapping and processing in metashape. First of all, is the P4RTK camera considered consumer grade? I would assume it is.
Second question is about what camera calibration coefficients are appropriate to model. f, k1, k2, k3, cx cy, p1, p2 of course are.
Guides such as the USGS 2020 paper say b1, b2, and k4 are no appropriate to model for most consumer grade cameras. So .. what about the P4RTK one?
obviously you can just model it anyways. The real issue is does it make any noticeable difference to compute k4, b1, b2 on this camera? Will it just always get an unstable solution and will that adversely affect final product precisions? Does anyone actually know or have checked.
In context i am typically ppk processing P4RTk gnss positions with Trimble Business Center. I just use a script to insert events into the rinex file. Then I take the positions and adjust each by the yaw,pitch, roll and offsets to camera (which for P4RTK is very easy since it is in the .mrk file anyways and when I hand compute I get same answer.) So I then load those vey good positions into the Metashape.
Works great. There is nothing more I can do there. The rest is in fine tuning the process in Metashape. Which I have down pretty well. But the one thing I cannot get a good answer on is if k4, b1, and b2 should even be included in the optimization. And is it only theory or has anyone really seen a difference skipping them or adding them in anyways. i notice the values for k4, b1, b2 vary a lot between different missions using the same drone. but the other values tend to be somewhat similar (the adjusted values) So I am suspicious that computing skew and k4 is FAKE.
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Ok I might as well ask couple other questions.
Anyone doing a slight offset from full nadir, like 95? Just wondering if that is still a thing. I have not heard of it in a couple years now.
Finally, how many of you are consistently able to get sub pixel final precisions (except for tiny pixels of course, how would you even know.) Please dont claim this unless you KNOW for sure. By checking gcp outside of metashape.
I am successfully getting sub pixel final precisions both in horiztonal and vertical when flying at 400ft down to 200ft. And only use ppk corrected 'camera' reference positions and NO INPUT GROUND CONTROL during processing. However ... keep in mind I will adjust bias out after the products leave metashape. I am a land surveyor and can get high quality control points.
Hopefully some of the knowledgeable users will reply.
If this was already answered in depth I apologize as I could not find it.