Elevations totally off in DEM reconstruction from historical imagery

[glacier]

I've been using Metashape to build DEMs from historical imagery downloaded from USGS earth explorer. Much of it is fairly high resolution. The elevations that metashape returns are totally wild. Here's my process:

import photos (cropped w/ no film scan artifacts) -> import reference (wgs 84 w/ flight altitude in meters) -> align photos -> optimize cameras -> generate point cloud -> generate DEM

The elevations I'm getting are -10- -13 km? Any idea why this is or how I can improve it? I can do further alignment e.g. using asp but just confused about why this is happening.

Thanks!

[Alexey Pasumansky]

Hello glacier,

Can you please share the screenshots of Source and Estimated tabs from the Reference pane for the cameras, so that all X, Y and Z values are fully visible (or attach the text file exported from the reference pane with this information)?

[glacier]

Here's the reference I used (metashape_metadata), along with the exported processed data (processed_metadata)

[Paulo]

Hello glacier,

by any chance are u just processing one flight line of historical imagery^?

If so and with camera alt accuracy set to 1000 m, anything goes for resulting estimated altitud....

[glacier]

Hi Paulo, thanks, it's two flight lines but I'll see if I can get an improvement by adding a third. The alt accuracy is almost certainly better than 1000m (we just don't have access to any calibration info for it) so I'll play around with that as well. Thanks!