{"accessLevel": "public", "bureauCode": ["010:12"], "contactPoint": {"@type": "vcard:Contact", "fn": "Chloe D Gustafson", "hasEmail": "mailto:cgustafson@usgs.gov"}, "description": "Radiometric data were collected at the Grand Junction Regional Airport radiometric calibration facility in August 2024. The facility consists of five ~9 by ~12 m (30 x 40 feet) concrete pads, each 18 in thick. Each pad provides sources of radioelements that are spatially homogeneous. Three pads are dedicated K, Th, and U pads, each of which contains high levels of their radioelement namesake. There is also a \u201cmixed pad,\u201d which contains moderate amounts of all three radioelements, and a background pad, which contains low levels of each radioelement. A small uncrewed airborne system (sUAS) equipped with a lightweight CsI radiometric sensor, the Medusa MS-350, was flown over the calibration pads at varying heights to observe the radiometric signal decay with height and to determine decay coefficients that can be applied to other radiometric surveys. We performed \"hover\" tests over the K, Th, U, and Mixed pads, where measurements were taken at 1m, 2m, 4m, 6m, 8m, 10m, 12m, 14m, 16m, and 20m above each pad for a duration of 1 minute at each height. This website contains the raw radiometric data with spectra collected over each in ASCII format (\"_raw_spectra\".csv) and processed radiometric data collected over each pad in ASCII format (\"_processed.csv\"). All GPS and Universal Transverse Mercador (UTM) coordinates in the data files are referenced to World Geodetic System (WGS) 84 UTM Zone 12N. The raw data includes all data collected during the sUAS flight duration. The processed data only include data when the \"hover\" measurements were being taken.", "distribution": [{"@type": "dcat:Distribution", "accessURL": "https://doi.org/10.5066/P145CWYA", "description": "Landing page for access to the data", "format": "XML", "mediaType": "application/http", "title": "Digital Data"}, {"@type": "dcat:Distribution", "description": "The metadata original format", "downloadURL": "https://data.usgs.gov/datacatalog/metadata/USGS.6949a814d4be02509472e2e8.xml", "format": "XML", "mediaType": "text/xml", "title": "Original Metadata"}], "identifier": "http://datainventory.doi.gov/id/dataset/USGS_6949a814d4be02509472e2e8", "keyword": ["Earth Mapping Resources Initiative", "EarthMRI", "GGGSC", "Geology, Geophysics, and Geochemistry Science Center", "MRP", "Mineral Resources Program", "U.S. Geological Survey", "USGS", "USGS:6949a814d4be02509472e2e8", "gamma ray spectrometry", "geoscientificInformation", "geospatial datasets", "radiometric surveying", "uncrewed airborne systems"], "modified": "2026-04-20T00:00:00Z", "publisher": {"@type": "org:Organization", "name": "U.S. Geological Survey"}, "spatial": "-108.5379000, 39.1280530, -108.5364460, 39.1289880", "theme": ["geospatial"], "title": "Radiometric data collected from an uncrewed airborne system at the Grand Junction Regional Airport radiometric calibration facility, 2024"}