Geotagging images acquired on a drone with a ppk module not connected to the camera


I have a P4P drone with the standard RGB camera and an additional multispectral camera. The drone has a ppk module connected to the RGB camera but not to the multispectral one.

This means that I can use the events.pos file to postprocess RGB images but not to postprocess the multispecral images. However, after the kinematic processing, emlidstudio gives another .pos file with all the logs coming from the ppk module.

I am wondering if it could be possible to geotag multispectral images in emlidstudio by combining this .pos file and the time metadata coming from GPS data of the multispectral camera.

If yes, considering that the ppk has a recording frequency of 10 Hz, would you suggest this over other approaches in terms of final accuracy of orthomosaics? For example, I was used to build multispectral orthomosaics based on RGB images or RGB DEM.

Thank you!

Hi @brzaf,

In what format are the images from the multispectral camera?

Also, do you have an MRK file from it?

Hi Anna,

The images are .tif but I can’t get any MRK file as far as I know.

Time marks are necessary to post-process images’ coordinates. In theory, your cameras may be synchronized to take photos exactly at the same time. But I can hardly provide exact steps for such an integration.

In this case, you can use the same rover log to process two types of photos. But Emlid Studio now can geotag only jpg images, so you need to convert TIFF to JPEG. And I’ll note TIFF format support as a feature request.

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Do you mean an hardware connection? If yes, that’s also something I would not try myself.
If no, I already tried something but having exactly the same time seems to be really hard. Anyway, I will try harder if you say there should be a way.

Doesn’t the multispektral camera have some kind of sync output?

Yes, it does. It’s a standard RedEdge MX camera. But I am not really confident that a second device could be connected to my topodrone ppk module.

I’ve discussed your case with the team. And I see two possible options for you. The first is to try synchronizing your cameras to take photos simultaneously while only one camera is connected to the PPK module. And the other one is to integrate one more PPK module for your multispectral camera.

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Thanks a lot for the support!

It would be great if someone knows a way to synchronize cameras without a physical connection. I tried to synchronize flight plans but it doesn’t seem to be possible having a perfect synchronization.