ECCOE 2021 Surface Reflectance Validation Dataset

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 selected Earth observing satellite overpasses and tests during the months of May through November 2021. These data were collected at six field sites during 2021. These field sites included South Dakota State University (SDSU) Research Park in Brookings, SD, near the Brookings Airport in Brookings, SD, a private land holding in Sanborn County, SD, Edwards Air Force Base in CA, Bureau of Land Management (BLM) managed land near Moneta, WY, State of Oklahoma Commissioners of the Land Office managed land near Guymon, OK, and Coconino National Forest near Flagstaff, AZ. Each field collection file includes the calculated surface reflectance of each wavelength collected by the spectroradiometer. Initial data collection methodology relied upon a single field spectrometer. Field collections conducted after 25 August 2021 contain data from two spectrometers. The addition of the second spectrometer reduced uncertainty in the field measurements by accounting for changes in solar irradiance. The differing methodologies are denoted as "Single Spectrometer" and "Dual Spectrometer". Field spectrometer data are provided as Comma Separated Values (CSV) files and GeoPackage files. Lastly, data were collected during the Big Multi-Agency Collection round robin and are provided for all targets observed during the campaign.

美国地质调查局（U.S. Geological Survey, USGS）地球资源观测与科学中心（Earth Resources Observation and Science Center, EROS）校准与验证卓越中心（Cal/Val Center of Excellence, ECCOE）的科学家与工程师，借助野外光谱辐射计采集原位测量数据，以支撑对地球观测遥感影像反演得到的地表反射率产品的验证工作。本次数据发布所提供的数据集，采集于2021年5月至11月期间的选定地球观测卫星过境时段与配套测试活动。2021年的数据采集共覆盖6个野外站点，分别为：南达科他州布鲁金斯的南达科他州立大学（South Dakota State University, SDSU）科技园、布鲁金斯机场周边区域、南达科他州圣伯恩斯县的私有土地、加利福尼亚州爱德华兹空军基地、怀俄明州莫内塔附近由土地管理局（Bureau of Land Management, BLM）管理的土地、俄克拉荷马州圭蒙附近由俄克拉荷马州土地办公室专员委员会管理的土地，以及亚利桑那州弗拉格斯塔夫附近的科科尼诺国家森林。每个野外采集文件均包含光谱辐射计采集的各波长对应的计算后地表反射率。早期的数据采集方案仅采用单台野外光谱辐射计；2021年8月25日后开展的野外采集则启用了两台光谱辐射计进行数据采集——新增的第二台光谱辐射计可通过同步监测太阳辐照度变化，有效降低野外测量的不确定性。两种采集方案分别标注为"单光谱辐射计（Single Spectrometer）"与"双光谱辐射计（Dual Spectrometer）"。野外光谱辐射计数据以逗号分隔值（Comma Separated Values, CSV）文件与地理数据包（GeoPackage）格式提供。此外，本次数据集还涵盖了多机构大型联合采集（Big Multi-Agency Collection）循环测试期间观测到的所有目标的相关数据。