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The number of Earth-observing sensors and their derived science products continue to grow rapidly. Without characterization and calibration of these sensors, the products they provide could not be reliably used by scientists and decision makers. 

Accurate, well-documented calibration is needed to understand and address local and global science and societal impacts and benefits. 

Test Sites Catalog July 2021

The characterization and calibration of these sensors is vital to achieve an integrated Global Earth Observation System of Systems (GEOSS) for coordinated and sustained observations of Earth.  Accurate and dependable calibrated/characterized Earth-observing data from many sources provide for a multitude of user benefits across every aspect of the natural and human environments.

As a supporting member of the Committee on Earth Observation Satellites (CEOS) and GEOSS, the USGS has been working with the CEOS Working Group on Calibration and Validation (WGCV) and its Infrared and Visible Optical Sensors (IVOS) subgroup to establish a catalog of prime candidate worldwide test sites for the post-launch characterization and calibration of space-based optical imaging sensors. The WGCV provided recommended CEOS Calibration/Validation (Cal/Val) sites and associated regions of interest (ROIs) for testing via the CEOS Cal/Val Portal

The USGS continues to support and update the ECCOE Test Sites Catalog with new test sites, including expansion to other sensor types. 

The ECCOE Test Sites Catalog can be accessed at