As part of a campaign organized by ESA and the Joint Research Centre Ispra, two sorties of the NASA DC-8 aircraft took place during August 1989 over three East Anglian test sites. The aircraft was equipped with the Jet Propulsion Laboratory P-/L-/C-band SAR and the characteristics of the radar are outlined and the associated calibration campaign described. An extensive ground data collection campaign was undertaken by a series of UK groups for forestry, agricultural and hydrological applications. The collection of forestry ground data is described in some detail. The anticipated uses of the ground data in the analysis of the radar images helped to determine the strategy for the selection of parameters to be measured.