Drone2Map-Artefakte im Ortho-Mosaik

Question

Ich habe ein Ortho-Mosaik in D2M erstellt. Zuerst mit den Standardeinstellungen und GSD 1. Es enthält Artefakte rund um das Mosaik wie unten gezeigt.<\/P> <\/span><\/P>Nach dem Lesen einiger Beiträge in dieser Community habe ich die Einstellungen geändert, z. B. "rolling shutter optimization" aktiviert, initial auf full geändert und "use geometry verified matching" aktiviert. Dies erzeugt noch mehr Artefakte und verschiebt das Ortho um mehrere hundert Meter.<\/P>Mit den Standardeinstellungen ist die Gesamtqualität in Ordnung, abgesehen von diesen Artefakten. Bitte geben Sie einen Rat, wie diese Probleme vermieden werden können.<\/P>Mit freundlichen Grüßen<\/P>

DerrickWestoby · Answer

You really want to be flying with 70%+ overlap with SfM.   Keep in mind that this is based off the drone's altitude above ground level and an image footprint projected into the ground.  If you're flying over tall buildings, especially at low (<200ft) altitudes, the overlap in those areas is going to be insufficient.  You may have 70%/70% overlap at ground level, but 50%/50% on the building roof.

FrankOuyang · Answer

As suggested by @DanPatterson, capturing more images using higher overlap ratio will help reduce the artifacts, such as increase it from 60% to 80% or 90%. This will increase processing time and the output point cloud size but it can significantly improve the quality of the output.

Another thing to consider, from my experience, is try to fly the UAV at the solar noon when the shadow is minimized. By doing so, object/area of interest will have the best illumination which helps the photogrammetry algorithms identify objects and reconstruct them and eventually, reduce the chance of having artifacts.

DanPatterson · Answer

There other related links to the right of your post, for example,

Solved: Drone2Map imagery quality - Esri Community

which suggests "overlaps" setting