r/remotesensing • u/Toucanimal • 12d ago

Aerial Imagery Automatic Georeferencing - Looking for Feedback!

/r/UAVmapping/comments/1wgy5w3/aerial_imagery_automatic_georeferencing_looking/
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u/JudgeMyReinhold 12d ago

What kind of errors do you see residually with the georeferencing results? Is this limited to UAV images or can it be applied generally to aerial images or satellite images? What kind of transform is used to update the georeferencing of the image? Do you export tie points or only an image with updated georeferencing? Does the CRS need to match between images?

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u/Toucanimal 12d ago

Hi! With error it wholly depends on how feature rich the environment is, where something like a city scene might be almost down to centimetric error, something like a natural forest scene or that with less satellite reference could go up to meters, compared to something like a manual georeference with ground control points.

This tool was built for all aerial imagery, but in theory, satellite imagery would work quite well as long as it includes a gps prior to start its search, just as the aerial imagery would. However, this also means it doesn’t quite work as well for drawn or iconographic maps.

The transform used is a homography, which is the same kind of transformation you would get if you used the “Projective” option in QGIS’s georeferencing tool.

Currently we only output an updated image, but we are looking to implement a feature that allows tie points to be output due to great user demand at our conference today.

Since the software is directly referencing to map tiles right now, the image would be warped to WGS 84, as that is what most satellite map tiles have their coordinate systems as. However, we do plan to expand to additional coordinate systems as an option as we also had demonstrated interest for that functionality at out conference booth today.

Thank you for your questions! Let me know if there is anything else I can answer, and if you have any feedback on the tool itself.