Processing images with RTK uav / GCP

Hi There,
have a job coming up this week flying over mud flats in a tidal area around an island.
Making it hard to incorporate GCP’s which i always use.
Have purchased an rtk phantom but are trying to determine how pix4d process’s involving GCP and RTK images?
Which does it hold over the other or do i just need the GCP as check points if all conditions with the flight are good.
Will be utilising the boat as well for the hydro survey side of the job and will create overlap with the surface to check against each other.
Can i abandon the gcp as far as processing accurately? Will the rtk images be enough to brace the data or is it just recommended as “good practice” ie survey methods etc
Any help would be great as its going to be near impossible to place enough gcp around the tide / time limitations in a proper spread / format for the area.
Regards,
Andrew

Hello Andrew, I wouldn’t suggest completely abandoning the GCPs even if you are using the RTK system. When you are using the RTK system, you don’t need the same number of GCPs as you would need for the project captured by drone without RTK. So, place a few GCPs as a control point and the checkpoints to verify your accuracy.

Thanks Kapil,
flight went well today,
processing has been successful but do have some whitish banding on the flight lines edges of the mosiac, was flying high on a sunny day over water / mud flats/ reflective.
Any ideas to fix in the processing?

Hello @Andrew, Can you forward the quality report and the few screenshots showing the issue?

Hi Kapil,
Mosaic is in the report.
We still have Hydro Survey to go and have access to the land survey as far as georeferencing / checking the point cloud adding more gcp etc if needed, only had access to part of the project at low tide to place gcp.
And from reading other posts yes we did fly into / away from the sun, unfortunately was the only way to be close enough to see the uav and change batteries for the flight mission.
Surface was the point of the flight but would of been nice to provide a better image.
7703 Sandstone Island 220223_report.pdf (2.2 MB)

Hello @Andrew,
It’s weird why you are having that issue because the quality report looks good. The only thing I would suggest to see if that helps is as follows.

  1. Verify the raw image quality. If there is any exposure that might be causing it.
  2. Add a few more GCPs(Min of 3).
  3. Use different calibration methods. The Alternative calibration method uses the geolocation information so, you can use that.
  4. If the above three suggestions don’t solve the issue. Use the rolling shutter in place of the global shutter to see if that helps.