DOI: 10.5066/p13penwg
title: High-resolution orthoimagery and digital surface model of Dorena Lake, Oregon, December 2023

description: In cooperation with the U.S. Army Corps of Engineers (USACE), the U.S. Geological Survey (USGS) surveyed ground control points and coordinated aerial photograph acquisition of Dorena Lake, a multi-purpose reservoir in western Oregon impounded by the 44-meter ([m]; 144-foot [ft]) tall Dorena Dam. Aerial photographs were acquired by the Civil Air Patrol (CAP) in December 2023 when water levels were one meter above typical annual “low pool” or minimum pool, a target elevation (236 m/773 ft National Geodetic Vertical Datum of 1929 [NGVD 29]) for flood risk management operations. Photographs were acquired at a single altitude with a WaldoAir XCAM Ultra 50 camera mounted on a Cessna aircraft and captured the entire reservoir area as defined by full pool (or maximum conservation pool elevation), including the major tributary entering the reservoir, the Row River. Dam operations at the 708-hectare (1750-acre) Dorena Lake, located about 11 kilometers upstream of the confluence of the Row River and the Coast Fork Willamette River, along with other hydrogeomorphic conditions, result in a diverse array of geomorphic processes and landforms within the reservoir. To document reservoir floor geomorphology, the USGS applied structure-from-motion (SfM) techniques to these aerial photographs, following the workflow outlined in Over and others (2021) and used for similar datasets (Schwid and others, 2025), and generated a three-dimensional xyz point cloud, digital surface model (DSM), and orthomosaic of Dorena Lake.
 
This data release includes ground control points, dataset footprints, original aerial photographs, a point cloud, a DSM, and an orthomosaic of Dorena Lake that were developed from imagery acquired on December 18, 2023. The point cloud has an average point density of 29.9 points per square meter, the DSM resolution is 18.3 centimeters per pixel, and the orthomosaic ground resolution is 9.14 centimeters per pixel. The DSM and orthomosaic are formatted as Cloud Optimized GeoTIFFs (COGs) for enhanced web visualization (GDAL, 2024).
 
References:
Agisoft, 2025, Agisoft Metashape User Manual - Professional Edition Version 2.2: Agisoft LLC, 115 p., accessed August 11, 2025, at https://www.agisoft.com/pdf/metashape_2_2_en.pdf.
 
American Society for Photogrammetry and Remote Sensing [ASPRS], 2008, LAS Specification Version 1.2: ASPRS, approved September 2, 2008, 13 p., accessed August 11, 2025, at https://www.asprs.org/wp-content/uploads/2010/12/asprs_las_format_v12.pdf.
 
Geospatial Data Abstraction Library [GDAL], 2024, COG -- Cloud Optimized GeoTIFF generator: GDAL, webpage, accessed August 11, 2025, at https://gdal.org/drivers/raster/cog.html#raster-cog.
 
Over, J.R., Ritchie, A.C., Kranenburg, C.J., Brown, J.A., Buscombe, D., Noble, T., Sherwood, C.R., Warrick, J.A., and Wernette, P.A., 2021, Processing coastal imagery with Agisoft Metashape Professional Edition, version 1.6—Structure from motion workflow documentation: U.S. Geological Survey Open-File Report 2021–1039, 46 p., https://doi.org/10.3133/ofr20211039.
 
Schwid, M.F., Keith, M.K., and Overstreet, B.T., 2025, High-resolution orthoimagery and digital surface models of Fern Ridge Lake, Oregon, during annual low pool, January and February, 2023: U.S. Geological Survey data release, https://doi.org/10.5066/P1Q5K657.