Radiometric Calibration Network (RadCalNet)
RadCalNet is an operational service developed and operated by the CEOS Working Group on Calibration and Validation ( WGCV ) that provides a continuously updated archive of top-of-atmosphere (TOA) reflectances over a network of calibration sites worldwide.
Over 1,000 registered users rely on data from the free and open service for post-launch radiometric calibration, sensor monitoring, and the validation of surface reflectance and atmospheric corrections. The quality of RadCalNet data is maintained by traceable uncertainties, routine data control, comparisons to satellite sensor measurements, and regular full reprocessing of the archive.
Since 2018, RadCalNet has delivered SI-traceable reflectance data at a 10 nm sampling interval every 30 minutes, supporting measurements and matchups in the visible to shortwave infrared spectrum (380 - 2500 nm). RadCalNet's TOA reflectances are derived from in-situ measurements acquired at the sites shown below.
Railroad Valley, USA
Railroad Valley is a dry lakebed natural calibration site in central Nevada, USA.
Gobabeb, Namibia
Gobabeb is a vicarious calibration site located in the Namib Desert, Namibia, characterised by low cloud coverage and high spatial homogeneity.
La Crau, France
Located in the south of France, La Crau is a vicarious and absolute calibration test site that consists of pebbles and sparse vegetation.
Baotou Natural site, China
The Baotou Sand Test Site (BSCN), located in Inner Mongolia, northern China, is a large sandy desert calibration site used by moderate spatial resolution sensors.
Baotou Artificial site, China
The Baotou Artificial Test Site (BTCN) features a knife-edge square target for measuring Relative Edge Response (RER) and smaller targets designed for the calibration of high-resolution sensors. The site is located in Inner Mongolia, northern China.