Drone2Map artefacten in ortho mozaïek

Question

Ik heb een ortho mozaïek gemaakt in D2M. Eerst met standaardinstellingen en GSD 1. Het bevat artefacten rondom het hele mozaïek zoals hieronder.<\/P> <\/span><\/P>Na het lezen van enkele berichten in deze community, heb ik de instellingen gewijzigd, zoals het aanvinken van "rolling shutter optimization", de initiële instelling veranderd naar volledig en "use geometry verified matching" aangevinkt. Dit veroorzaakt zelfs meer artefacten en verplaatst de ortho volledig met enkele honderden meters.<\/P>Met de standaardinstellingen is de algehele kwaliteit OK behalve deze artefacten. Graag advies over hoe deze problemen vermeden kunnen worden.<\/P>Met vriendelijke groet<\/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.

danretired · Answer

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

Solved: Drone2Map imagery quality - Esri Community

which suggests "overlaps" setting