Characterization of CRCS Dunhuang test site and vicarious calibration utilization for Fengyun (FY) series sensors

The Dunhuang test site, one of the China Radiometric Calibration Sites (CRCS) for the vicarious calibration (VC) of Chinese spaceborne sensors, was selected in 2008 by the Working Group on Calibration and Validation (WGCV) of the Committee on Earth Observation Satellites (CEOS) as one of the instrumented reference sites. The site is spatially uniform with a coefficient of variation (CV) (standard deviation / mean) less than 2% of spectral reflectance over the 10 km × 10 km central region, based on the imagery of the Medium Resolution Spectral Imager (MERSI) onboard the Fengyun 3A (FY-3A) satellite. This result is also proven by several ground truth measurements. The surface spectral reflectance is temporally stable with a CV of about 3% from 7-year Moderate Resolution Imaging Spectroradiometer (MODIS) surface albedo product and has been validated using the ground-based measurement eight times in 10 years. Several calibration/validation (Cal/Val) field campaigns for the site evaluation and VC have been con...