The U.S. Geological Survey collected low-altitude airborne natural color imagery via a fixed-wing uncrewed aircraft system (UAS) for mapping channel and vegetation change along a 2-mile reach of the Middle Green River at Grays Canyon near Green River, UT. Visual imagery was collected in jpg format and Structure-from-Motion (SfM) photogrammetry techniques were applied (Over et. al. 2021) using Agisoft Metashape Professional (v. 2.1.2 build 18358) to derive time-specific high-resolution 5 centimeter natural color orthomosaics of the study reach annually from 2021 to 2023. Ground control points (2ft x 2ft ground targets) were also surveyed in the field using Trimble RTK GPS survey units and were used in georectification in the SfM process.
