Support Website Contact Support Blog

PPK GPS Antenna Offset

As PPK becomes more popular and affordable, it seems only right that the software such as Pix4D keeps up with the trend. Currently there is no option in Pix4D to account for an offset of the PPK GPS antenna coordinate and the camera center. 

This option will soon become a desirable selling point for Pix4D and definitly useful for its existing users to make even more accurate models / surveys. It should be noted that Pix4D closest competitor has been offering this for some time now.

1 Like

Hi Luke,

Thanks for your interest in Pix4D software solutions.  We are continually working to improve Pix4D software to better meet our customer’s needs and appreciate your suggestion.   While there is no option within Pix4Dcapture to alter image geotag information (i.e.  adjusting offset), it is possible to alter/edit geotag information within Pix4Dmapper.

Pix4Dmapper is intended to be “agnostic” and can process images from virtually any digital camera regardless of platform it was taken from and regardless if Geotag information is available.  Typically the Geotagging of the images is done onboard the UAV itself and the proper offsets would be accounted for when the image is tagged by the UAV flight controller, but images geotags can also be adjusted within Image Properties Editor. (below is a link to a support article that may be helpful)

 Step 2.  Creating a Project >3. Configuring the Image Properties

Regardless of how accurate the UAV’s onboard GPS may be, accurate geotags are still not considered a replacement for accurate GCPs to create projects with the highest geospatial accuracy.

Regards,

Aaron Woods

Aaron Woods  | Technical Support Specialist, North America
Pix4D Inc | San Francisco, California, USA

1 Like

Thank you for your response Mr Woods.

It seems my call to implement an antenna offset specifically for PPK results has been asked before:

https://community.pix4d.com/t/4886-Accounting-for-GPS-antenna-offset#gsc.tab=0

and https://support.pix4d.com/hc/en-us/articles/hc/ja/community/posts/115017884083-Accounting-for-offset-GPS-antenna#gsc.tab=0

In one post, user Mark, presumably has inside knowledge of the workings of Pix4D and offers that such a tool would be available.

Using the image properties editor is not a solution since there is a fair bit of calculation do be done in order to shift antenna coordinates. Especially when the flight path is considered arbitrary.

Mr Woods, it seems you are not understanding that PPK processed image geolocation coordinates are processed to cm level and are in no way similar to the coarse flight controller derived coordinates. I would agree with your statement about the accuracy of models using flight controller tags only in modelling. How ever, there is much documentation show that PPK processed images are provide acceptable accuracy with out GCP and even better accuracy when combined with GCP. 

I hope you will revisit this query with more information and understanding of the problem that your competitors have resolved and applied to their workflow.

1 Like