The Network for Calibration and Validation of EO data (NCAVEO) ground data collection programme included a series of transects on the River Test at Chilbolton Cow Common, an area of semi-natural wet grassland. The river survey was carried out on the 16th June between 11:15 and 13:15 at site Chilbolton 1 and 15:30-17:00 at Chilbolton 2, the day before the ‘golden day’ on which the airborne data were collected by the Environment Agency / Natural Environment Research Council (NERC).

The sampling strategy used was based on the desire to capture; (1) data over the range of water depths, (2) a dense and extensive sample of data to allow for bathymetric modelling of the river regions and (3) data over a broad range of substrate types to represent all varieties within the study region (e.g. from marginal vegetation to silts and to gravels). The variables recorded included: Easting; Northing; Water depth (cm); Depth to bed (cm); Surface velocity (m/s); Dominant substrate. Surface velocity was measured using a Valeport uni-directional electro-magnetic current meter (Valeport Ltd.). For more information on the collection and processing of the data please see the dataset's metadata document, in linked documentation. A video of David Spear describing the survey is available also included in the directory.