Messages

1

General / Re: Artifacts in DEMs derived from scanned air photos

« on: November 25, 2020, 03:06:28 AM »

I have tried using fiducials on several sets of photos, and it never seems to make much difference in the final product, but can take up a lot of time. Many of the older photos I am using do not work with the automatic detection.

2

General / Re: Artifacts in DEMs derived from scanned air photos

« on: November 19, 2020, 08:39:38 PM »

Thanks, I will pay more attention to getting better alignment.

3

General / Artifacts in DEMs derived from scanned air photos

« on: November 18, 2020, 03:58:29 AM »

I have been using metashape to build DEMs from scanned airphotos for several years. I follow the USGS procedures for editing and optimizing the sparse point cloud and georeference using control points. Usually I get good (albeit noisy) results, but sometimes get a characteristic patchy artifact where there are zones that step up or down in elevation abruptly.  Any advice on the cause of this? I have attached a sample.