I've further improved my long trains scanning setup with:

* portable battery-powered enclosure with display: https://daniel.lawrence.lu/blog/2026-06-12-standalone-cnc-li...

* fine-grained distortion correction by manual annotation: https://daniel.lawrence.lu/blog/2026-08-02-line-scan-camera-...

Here's a recent Caltrain photo: https://commons.wikimedia.org/wiki/File:Caltrain_Stadler_KIS...