GCP red warning

PIX4Dmapper PIX4Dmapper Questions/Troubleshooting
1

Hi, I am getting a red warning about my GCPs

gcp
gcp2418×593 107 KB

gcp2
gcp22424×805 206 KB

I’m using the default of 0.02m accuracy. I’m not sure what the actual accuracy is. I understand that I’m getting these errors because XYZ is greater than twice the default. I’m wondering if this is to be expected and I can continue processing the DSM, ortho, etc. or if i should change the accuracy settings?

Thank you!

2

Hello @jaylene.naylor, It would really be helpful if you have attached the full quality report. The issue is mainly related to the GCPs, so I would suggest the following to see if that helps to solve your issue.

  1. If you are using the rolling shutter change it to a global shutter camera. For more information visit the below link: https://support.pix4d.com/hc/en-us/articles/208460436-How-to-correct-for-the-Rolling-Shutter-Effect
  2. Use the different calibration methods to see if that helps, Use an alternative calibration method and the All Prior as camera calibration options during step 1 of processing.
    If that doesn’t solve the issue, can you forward a few screenshots and the quality report of the project?
3

Woohoo that worked! The flying height is 125m would that explain the rolling shutter effect?
It is also a fairly homogeneous area, low tundra in Northern Alaska.

Also, while I have you here, the photos and GCPs were taken in NAD83(2011)UTM 6N. When I add the GCPs they show up correctly but when I add the photos they’re near the equator. So I changed it to WGS84 and they showed up in the correct position. I believe Pix4d will make the conversion but I am wondering why this happens.

Capic
Capic609×1743 65.2 KB

4

report.xml (39.3 KB)

Seems like it should be ready to process?

5

Hello @jaylene.naylor, The raw images that you capture from the drone are usually in WGS. Why were they captured in the different coordinate systems; NAD83(2011)UTM 6N? If they are in a different coordinate system then make sure to change it to the correct coordinate and see if that helps to solve your issue. From the files that you have forwarded, it shows that it is using the WGS 84 for the images so if they were captured in different system you have to change it.

coordinate
coordinate1825×734 281 KB