Logging trench walls with a phone vs. total station, night and day

For the first 8 years I dug, I sketched every trench wall by hand with graph paper and a tape. Last summer at a site near Flagstaff, I tried photogrammetry with just my phone, taking overlapping shots every 2 feet. The 3D model took me about 15 minutes to stitch in Agisoft, versus the 2 hours I used to spend on a single detailed drawing. It caught small features like root casts and pit edges that my eyes missed entirely on site. Now I only hand draw when the soil is too dark or the trench is under a tarp. Has anyone else switched to recording with a phone and found the field notes harder to trust later?

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1 Comment

wyatt_lee1mo ago

God, I was so skeptical about this at first. I figured a phone could never catch the detail I get from sketching grain patterns or mottling by hand. But last spring I tried it on a site with really subtle clay films, and when I pulled up the model later, I could zoom in on stuff I straight up missed in the field. The pit edges showed up way clearer than my pencil lines ever did. Now I’m the guy telling everyone to at least try it on a test unit before they write it off. I still carry graph paper for backup, but honestly, it’s just collecting dust in the truck now.