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Tie point

The modell 70-80 meters below the tie Points, why?

   

Hi Alexander,

Could you perhaps give a bit of context like the drone you used to fly?
Do you mean the model is below the ground control points (GCPs) that you measured on the ground and imported into the project?
Did you make sure to have set the appropriate coordinate system for the images and eventually the GCPs if you are using some?
For more information: https://support.pix4d.com/hc/en-us/articles/202560029

Regards,

Hi

last omage show the problem.
south norway we use WGS84 euref89 sone N32.

 

Hi Alexander,

You will find help on this matter here: https://support.pix4d.com/hc/en-us/articles/206544136

The images that are saved on the drone’s SD card are geotagged by DJI. These coordinates are the same of that in the .p4d file generated by our mobile app, Pix4Dcapture. Regarding the Lat./Long. coordinates, the drone’s GPS saves reliable information in the image EXIF. However regarding the altitude there might be some inaccuracies depending on the location where you are mapping. We made testing in our office here and we found that the vertical coordinate is off by several meters that can reach an error of 100 meters. Some users noticed the same.

Therefore our developers suspect something wrong in the DJI EXIF regarding the vertical coordinates. As a consequence, we always recommend to process with ground control points (GCPs) in order to fix these uncertainties.

Regards,

Hi

I ran across the same area with drone. Then came GPS surveying under Model. when I got to connect measurements mine against the model.
previously poblem that GPS measurements landed high above the model that it was not possible to connect them to the model. area had a pretty big drop. may be what’s the problem?

One solution may be to create your own tie point in pix4d and add in an approximately height so that the model moves enough that they surveyed GPS points can be connected to the model afterwards.

??