Digital Surface Models and orthomosaic images from UAS surveys of Jenkinson Lake, El Dorado County, CA

This data release presents Digital Surface Models (DSM) and orthomosaic images derived from uncrewed aerial system (UAS) surveys conducted at Jenkinson Lake in El Dorado County, California. The surveys were conducted to perform repeat structure-from-motion topographic mapping at the upper end of the reservoir, near the inlets of Sly Park Creek and Hazel Creek, with the purpose of measuring sediment inputs into the reservoir following the Caldor fire in 2021. Four surveys were conducted between 2021 and 2023, and were generally timed to coincide with low water levels to maximize sub-aerial coverage on the reservoir delta.  

The surveys were conducted using Department of Interior-owned quadcopters fitted with a digital camera featuring a global shutter. The UAS were flown on pre-programmed autonomous flight lines which were spaced to provide sufficient overlap between images from adjacent lines for SfM photogrammetric processing.

Survey control was established using temporary ground control points (GCPs) distributed throughout the survey area. The GCP positions were measured using real-time kinematic (RTK) or post-processed (PPK) GNSS, with corrections from a concurrently operating base station located near the study area.

This data release contains data from four surveys conducted on 2021-10-13, 2021-11-04, 2022-10-25, and 2023-11-13. Two data products derived from each survey are available for download: 1) high-resolution orthomosaic images with resolutions of 2.5 centimeters per pixel 2) and high-resolution digital surface models (DSM) with resolutions of 10 centimeters per pixel.