Forum

Author Topic: Quick Question - RTK/PPK precision, drone image position accuracy  (Read 856 times)

someDude

  • Newbie
  • *
  • Posts: 14
    • View Profile
Quick Question - RTK/PPK precision, drone image position accuracy
« on: September 14, 2021, 11:59:45 PM »
Hello,

For my use case, I will not do any 3D reconstruction, but I COULD do it with the images that I acquire. But I need an accuracy of the camera locations of better than 3-4cm in all directions. Now I'm reading all sorts of stuff how people are improving their "precision", by putting just a few ground control points into their scan.

So here's my question for you pros:
Does this use of GCPs improve only the precision of the SCAN DATA, or also the precision of the CAMERA POSITIONS (my area of interest)?

I'll be using a rtk/ppk drone (probably DJI P4.pro.RTK), so the proclaimed camera location precision is a few cm. I'm just wondering if that is marketing speech and I really should use the scan data, to ensure that the camera positions are ALWAYS at this level of accuracy.

Thanks for your wisdom.


someDude

  • Newbie
  • *
  • Posts: 14
    • View Profile
Re: Quick Question - RTK/PPK precision, drone image position accuracy
« Reply #1 on: September 15, 2021, 01:21:41 AM »
Ok, so I might have found the answer here: https://youtu.be/Vjbol1_7958?t=1762
So the rtk drone image positions are essentially ACPs (air control points), and the possible error without GCPs is a vertical bias, that occurs (logically) due to the way the point cloud point positions are calculated. So for my case, no problem, the GCPs are only needed for model reconstruction.
thank you myself  ;D ;)

someDude

  • Newbie
  • *
  • Posts: 14
    • View Profile
Re: Quick Question - RTK/PPK precision, drone image position accuracy
« Reply #2 on: September 15, 2021, 01:37:46 AM »
Naaa, I'm taking that back. watched the linked yt-webcast to the end now. So ground control points CAN help to reveal possible z-value errors in the rtk-data, if you messed up something I did not fully understand yet.
Takeaway: doublecheck your data...  :-\