Field measurements of water depth from the Colorado River near Lees Ferry, AZ, March 16-18, 2021

Field measurements of water depth were acquired from a reach of the Colorado River near Lees Ferry, Arizona, March16-18, 2021, to support research on remote sensing of water depth from satellite images. The depth measurements included in this data release were obtained along a series of cross-sections using a SonTek RiverSurveyor M9 acoustic Doppler current profiler (ADCP) deployed from a boat. The spatial location of each measurement was obtained using a differential GPS included as part of the RiverSurveyor M9 ADCP instrument package. The map projection and datum for these data are UTM Zone 12S and WGS84, respectively. The USGS Qrev software program was used to ingest and process the raw ADCP data. The Qrev data file was then imported into MATLAB, which was used to create a comma-delimited (*.csv) text file with three columns: Easting_m, Northing_m, and Depth_m; the units of the spatial coordinates and the depths are meters. This ground-based depth data set was used to calibrate (i.e., train) models for inferring water depths from passive optical image data and to assess the accuracy of image-derived depth estimates.