Vicarious calibration approaches using in-situ measurements are key techniques applied to on-orbit remote sensors. The in-situ measurements have advantages in terms of traceability and quantifiable accuracy that make them ideal for inter-consistency studies of on-orbit sensors. The Committee on Earth Observation Satellites Working Group on Calibration and Validation Infrared Visible Optical Sensors initiated the Radiometric Calibration Network (RadCalNet) to provide automated surface and top-of-atmosphere (TOA) reflectance data from multiple participating ground sites to the worldwide user community. RadCalNet standardizes protocols for collecting data, processes TOA reflectance, and provides International System of Units traceable uncertainty budgets for the five currently operating sites. RadCalNet data from the Railroad Valley Playa, Nevada, site was used to provide an SI-traceable, absolute radiometric calibration of the Enhanced MODIS Airborne Simulator as part of an overflight of opportunity during the FIREX-AQ campaign. The results shown here demonstrate the utility of RadCalNet data for absolute radiometric calibration of airborne imagers making flights of opportunity without the need for coordination with a field validation team.

中文翻译：

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使用 RadCalNet 评估机载传感器的替代校准

使用原位测量的替代校准方法是应用于在轨遥感器的关键技术。原位测量在可追溯性和可量化精度方面具有优势，使其成为在轨传感器的一致性研究的理想选择。地球观测卫星委员会校准和验证红外可见光传感器工作组启动了辐射校准网络 (RadCalNet)，以向全球用户社区提供来自多个参与地面站点的自动化地表和大气层顶 (TOA) 反射数据。RadCalNet 标准化用于收集数据的协议，处理 TOA 反射，并为五个当前运行的站点提供国际单位系统可追溯的不确定性预算。来自内华达州 Railroad Valley Playa 的 RadCalNet 数据，该站点用于提供增强型 MODIS 机载模拟器的 SI 可追踪、绝对辐射校准，作为 FIREX-AQ 活动期间机会飞越的一部分。此处显示的结果证明了 RadCalNet 数据可用于机载成像仪的绝对辐射校准，从而无需与现场验证团队协调即可实现机会飞行。