CEOS has endorsed a number of test sites that are used for calibration and validation activities (coloured). The sites have been grouped according to WGCV's subgroup's domain and divided by applications, see the tree diagram below. In addition, there are other reference sites that are also used for EO calibration or validation.
AC subgroup IVOS subgroup LPV subgroup MS subgroup SAR subgroup
AC networks Land Sites Other Methods Ocean Sites LPV Supersites MSSG test Sites Targets Database
NDACC PICS ROLO MOBY ISMN
TCCON RadCalNet GIRO BOUSSOLE NEON
GAW Sensor Characterization FRM4STS AERONET-OC TERN
SHADOZ MTF Ref. Dataset     ICOS
TOLNet USGS Catalogue     BSRN
PGN (Pandonia)       SURFRAD
FRM4DOAS       FLUXNET
AERONET       NPN
GRUAN       PEP
ACTRIS       PEN
CARBIC       EnviroNet
CONTRAIL       KIT
        ForestGeo
        ForestPlots

coloured CEOS endorsed Cal/Val sites
white Reference Networks