Defects in Dense Cloud / DSM

[RoryG]

Hi,

I'm processing a P4RTK mission made up of four flights, PPK processed in RedToolbox. Due to the remote location of the site and difficulty to access on foot there are no checkpoints / GCPs in the project. The client requested 50cm XYZ accuracy, and according to Metashape (latest version just installed) the XY accuracy is 22cm and Y 30cm. I followed my normal workflow which has up to now worked perfectly, however in this instance I'm getting lines and trenches in the dense cloud / DSM that don't exist on the terrain. Any idea what could be causing this? Camera overlap is 75/75 and flying height of 90m (terrain following). I've attached a couple of images from QGIS, one showing the orthomosaic and the other the orthomosaic overlaid with hillshade extracted from the all classes DSM.

[RoryG]

I've reprocessed the project with some GCPs grabbed from identifiable ground features and used less aggressive gradual selection and the output is now perfect. I suspect I may have removed too many points and there were areas without enough data to generate the dense cloud.