Hekla (Iceland) Pumice Quarry Unoccupied Aircraft System (UAS) Surveys

This dataset contains data products from two Unoccupied Aircraft System (UAS) mapping surveys flown at a pumice quarry containing eruptive material from the 1104 C.E. eruption of Hekla volcano, Iceland. The UAS surveys of the quarry provide reference information for the locations of pumice samples collected in the quarry. The quarry location is 64.06° N latitude, 19.79° W longitude and the flights were conducted on July 21, 2023. The surveys are titled “Quarry” and “Quarry Wall”.In addition to the survey data, this dataset contains two key files:Processing_Data_Pumice.xlsx: A summary table providing camera, processing, and georeferencing information for the UAS surveys included in the datasetREADME.txt: A Read Me file listing all file types and file names, methods, and additional information for the dataset.A DJI Mavic 3 Enterprise (M3E) UAS was used to fly the surveys. The camera on the M3E has a 4/3” complementary metal-oxide semiconductor (CMOS) sensor, with a focal length of 12.29 mm, resolution of 5280 × 3956 pixels (20 megapixels), and a mechanical shutter. The M3E used a DJI D-RTK 2 High Precision GNSS Mobile Station to provide real-time kinetic positioning of the UAS. This system allowed for precise automated flight and high-accuracy image geotags, with a positional accuracy of &lt;5 cm.The Quarry survey used a “Smart Oblique” automated mapping survey grid in the DJI Pilot 2 flight software to capture both nadir images and oblique images (45° look angle) looking north, south, east, and west so that all faces of the quarry wall were captured. The DEM, orthomosaic, point cloud, and metadata processing report from this survey are included in this dataset. The Quarry Wall survey was flown manually at a distance of a few meters from the quarry wall. Four “loops” of the quarry were flown, with variable heights above ground level (AGL) and camera look angles (2.5, 5, 10, and 15 m AGL and 15°, 20°, 30°, and 45° below horizontal, respectively). The point cloud, textured 3D model, and metadata processing report from this survey are included in this dataset.Structure-from-Motion (SfM) photogrammetric processing was done using Agisoft Metashape Pro v2.0.2 software and followed the workflow of Over et al. (2021, U.S. Geological Survey Open-File Report 2021-1039, https://doi.org/10.3133/ofr20211039). The image locations were used to provide the spatial reference for the Quarry model, with an average root-mean-square (RMS) error of 47 cm. The Quarry Wall model was aligned to the Quarry model using 6 natural ground control points (e.g., rocks or other features precisely identifiable in images from both surveys) with an RMS error of 2 cm. All data products are in the ISN2016/Lambert 2016 coordinate reference system (EPSG:8088).<br><i>For inquiries regarding the contents of this dataset, please contact the Corresponding Author listed in the README.txt file. Administrative inquiries (e.g., removal requests, trouble downloading, etc.) can be directed to [e-mail]</i>