Accounting for offset GPS antenna

I have a new unit with a V-map PPK onboard, but the camera is on a front mounted gimbal and the antenna is mounted on the body of the quad.  How do you account for this offset in Pix4D?  I know this is easily done in Agisoft Photoscan but I can’t seem to find the option in Pix4D.

This is something we are working on at the moment but it is not currently available in the software. 

What’s the status now, Marc?

This is still ongoing. Unfortunately, we cannot give a time estimate (though it will not make it into 3.3).

Hi, I see this question in several posts. I am using the new deltaQuad Map drone which is equipped with an EmlidReach M2 receiver. The antenna is more than 15 cm away, laterally, from the camera lens, which has me quite worried about the XY accuracy of the geotagged images. With a 15 cm lateral offset the X,Y geotag would then have a +/- 30 cm error… and the variations in drone pitch would entail a larger accuracy in Z… The geotagged images do not have attitudes neither (rawi, pitch, roll) so I can’t correct the effect.

Can I still expect centimetric accuracy on my point cloud? The PPK accuracy on the emlid antenna will be centimetric, but should I use these accuracies for the images? Are the offset (lever arms) optimized as part of the calibration (it seems not in the quality report?). I worry that this error would be taken up by other parameters?

Hope you can advise on this, I see many users around with similar questions…




Hi Christophe,

Welcome to the community!

Do you have any projects processed with GCPs? Are you able to share the quality report mentioned? While we can use our software to detect such errors, the more specific hardware related questions might be better suited for the drone manufacturer. It would be better to have more concrete information to work off of.

It could be expected that a camera does not tag image geolocation, and in these cases the PPK output file would be needed to provide such image geolocation. Are you able to receive these orientation values and height(Z) from this hardware/PPK setup?

For more information regarding file formats:
Input files(Image Geolocation)- PIX4Dmapper.
EXIF and XMP tag information for project creation.
Image geolocation and orientation import format - PIX4Dmatic.