Position and projection errors

PIX4Dmapper PIX4Dmapper Questions/Troubleshooting
1

Good day,

I’m dealing with “position and projection errors” in my project as can be seen in the attachment. Normally I don’t have this problem.

Project with projection errors
Project with projection errors1191×700 303 KB

Does anyone know what causes these errors? Does this have to do with the drone flight or something? And do these “errors” affect the outcome and accuracy of the data (DSM for example)?

Thank you in advance,

Bas

2

Hello there, The issue is due to the vertical shift between the image geotags information and projected image location. This is caused due to the inaccuracy of the geotags of the images. In most cases, this is related to GPS device of the drones where the vertical coordinate can be off by several meters and can reach an error of 100 meters. Note that this is just an offset, meaning that within the model, the accuracy is not affected.

3

Hi Kapil,

Thank you very much! Do you also know what causes the GPS device of the drone to be off?

Gr. Bas

4

@b.copier The reason might be the number of available satellites in that area or the weak satellite single, the quality of the GPS, some issues with the drone software/firmware, and so on.