Scientists and engineers from the U.S. Geological Survey (USGS) Earth Resources Observation and Science Center (EROS) Cal/Val Center of Excellence (ECCOE) collected in situ measurements using field spectrometers to support the validation of surface reflectance products derived from Earth observing remote sensing imagery. Data provided in this data release were collected during select Earth observing satellite overpasses. Additionally, multiple hourly collections were made on September 26, 2025, outside of satellite overpasses, for site characterization purposes. All of these collections occurred during the months of March through September 2025 at the USGS EROS facility in Minnehaha County, South Dakota. Each field collection file includes the calculated surface reflectance of each wavelength collected using a dual field spectrometer methodology. The dual field spectrometer methodology allows for the calculated surface reflectance of each wavelength to be computed using one or both of the spectrometers. The use of the dual field spectrometers system reduces uncertainty in the field measurements by accounting for changes in solar irradiance. Both single and dual spectrometer calculated surface reflectance are included with this dataset. The differing methodologies of the calculated surface reflectance data are denoted as "Single Spectrometer" and "Dual Spectrometer". Field spectrometer data are provided as Comma Separated Values (CSV) files and GeoPackage files.

U.S. Geological Survey (USGS) scientists conducted field data collection efforts between September 30th and October 9th, 2021 over a large stretch of the Potomac River in Maryland and West Virginia using high accuracy surveying technologies. The work was initiated as an effort to validate commercially acquired topobathymetric light detection and ranging (lidar) data that was collected coincidentally between October 3 - 5, 2021 for the USGS 3D Elevation Program (3DEP). The goal was to compare and validate the airborne lidar data to topographic, bathymetric, structural, and infrastructural data collected through more traditional means (e.g., Global Navigational Satellite System (GNSS) surveying). Evaluating these data will provide valuable information on the performance of inland topobathymetric lidar mapping capabilities and their potential for use and inclusion in the USGS National Geospatial Program 3D Elevation Program. The primary uses for the airborne topobathymetric lidar data will be hydrodynamic and water supply risk modeling and aquatic habitat assessments. The data contained within this particular release are comprised of conventional survey (i.e. total station and GNSS) and ground based lidar data.

Scientists and engineers from the U.S. Geological Survey (USGS) Earth Resources Observation and Science Center (EROS) Cal/Val Center of Excellence (ECCOE) collected in situ measurements using field spectrometers to support the validation of surface reflectance products derived from Earth observing remote sensing imagery. Data provided in this data release were collected during select Earth observing satellite overpasses during the months of May through November 2023 at the USGS EROS facility in Minnehaha County, South Dakota. Each field collection file includes the calculated surface reflectance of each wavelength collected using a dual field spectrometer methodology. The dual field spectrometer methodology allows for the calculated surface reflectance of each wavelength to be computed using one or both of the spectrometers. The use of the dual field spectrometers system reduces uncertainty in the field measurements by accounting for changes in solar irradiance. Both single and dual spectrometer calculated surface reflectance are included with this dataset. The differing methodologies of the calculated surface reflectance data are denoted as "Single Spectrometer" and "Dual Spectrometer". Field spectrometer data are provided as Comma Separated Values (CSV) files and GeoPackage files.

Scientists and engineers from the U.S. Geological Survey (USGS) Earth Resources Observation and Science Center (EROS) Cal/Val Center of Excellence (ECCOE) collected in situ measurements using field spectrometers to support the validation of surface reflectance products derived from Earth observing remote sensing imagery. Data provided in this data release were collected during select Earth observing satellite overpasses during the months of March through November 2024 at the USGS EROS facility in Minnehaha County, South Dakota. Each field collection file includes the calculated surface reflectance of each wavelength collected using a dual field spectrometer methodology. The dual field spectrometer methodology allows for the calculated surface reflectance of each wavelength to be computed using one or both of the spectrometers. The use of the dual field spectrometers system reduces uncertainty in the field measurements by accounting for changes in solar irradiance. Both single and dual spectrometer calculated surface reflectance are included with this dataset. The differing methodologies of the calculated surface reflectance data are denoted as "Single Spectrometer" and "Dual Spectrometer". Field spectrometer data are provided as Comma Separated Values (CSV) files and GeoPackage files.

U.S. Geological Survey (USGS) scientists and engineers from the Earth Resources Observation and Science Center (EROS) Calibration/Validation Center of Excellence (ECCOE) and the National Uncrewed Systems Office (NUSO) conducted field data collection efforts July 15 – 18, 2023 at the USGS EROS facility in Minnehaha County, South Dakota. The data collected included multispectral (MS) and hyperspectral (HS) imagery from two commonly used Uncrewed Aircraft Systems (UAS) mounted cameras, as well as field spectrometer measurements collected from the ground. The work was initiated to assess the radiometric quality of the imagery collected by the MS and HS cameras when the cameras were calibrated using their respective manufactures’ recommended procedures and to see if the quality could be improved by implementing the Empirical Line Method (ELM). Additionally, several different calibration targets were deployed to determine the impacts of target size, material, reflectance intensity, and quantity on the ELM for UAS data. Only the data from the noon collection on July 18 is provided in this data release as the other collections were impacted by wildfire smoke, clouds, aerosol, and/or gimbal issues. See the associated journal publication for further details.

Scientists and engineers from the U.S. Geological Survey (USGS) Earth Resources Observation and Science Center (EROS) Cal/Val Center of Excellence (ECCOE) collected in situ measurements using field spectrometers to support the validation of surface reflectance products derived from Earth observing remote sensing imagery. Data provided in this data release were collected during select Earth observing satellite overpasses and tests during the months of May through October 2022. Data was collected at three field sites: the ground viewing radiometer (GVR) site on the USGS EROS facility in Minnehaha County, South Dakota, a private land holding near the City of Arlington in Brookings County, South Dakota, and a private land holding in Sanborn County, South Dakota. Each field collection file includes the calculated surface reflectance of each wavelength collected using a dual field spectrometer methodology. The dual field spectrometer methodology allows for the calculated surface reflectance of each wavelength to be computed using one or both of the spectrometers. The use of the dual field spectrometers system reduces uncertainty in the field measurements by accounting for changes in solar irradiance. Both single and dual spectrometer calculated surface reflectance are included with this dataset. The differing methodologies of the calculated surface reflectance data are denoted as 'Single Spectrometer' and 'Dual Spectrometer'. Field spectrometer data are provided as Comma Separated Values (CSV) files and GeoPackage files. The 09 May 2022 and the 16 June 2022 collection data are calculated using single spectrometer only, due to a technical issue with a field spectrometer.

U.S. Geological Survey (USGS) scientists conducted field data collection efforts between October 25th and 31st, 2020 at several sites in eastern Iowa using high accuracy surveying technologies. The work was initiated as an effort to validate commercially acquired topographic light detection and ranging (lidar) data that was collected between December 7th, 2019 and November 19th, 2020 using wide area mapping lidar systems for the USGS 3D Elevation Program (3DEP). The goal was to compare and validate the airborne lidar data to topographic, structural, and infrastructural data collected through more traditional means (e.g., Global Navigational Satellite System (GNSS) surveying). Evaluating these data will provide valuable information on the performance of wide area topographic lidar mapping capabilities that are becoming more widely used in 3DEP. The airborne lidar was collected to support the U.S. Department of Agriculture (USDA) Natural Resources Conservation Service (NRCS) High Resolution Elevation Enterprise Program and the Iowa Department of Agriculture and Land Stewardship Iowa Flood Plain Program, in addition to the 3DEP mission. The data contained within this particular release are comprised of conventional survey (i.e. total station and GNSS) and ground based lidar data.