NCAVEO: Leaf Area Index measurements collected using a Delta-T SunScan at the Brockley, Rickyard and Fairpiece field sites near Chilbolton

Leaf Area Index (LAI) measurements were collected using a Delta-T SunScan as part of the Network for Calibration and Validation of Earth Observation data (NCAVEO) 2006 Field Campaign. Data were collected from the following experiment fields: Rickyard (winter wheat), Fairpiece (winter oats) and Brockley (spring barley). The parameters required by the SunData program were set as follows: • Leaf Angle Distribution Parameter = 1.0 • Leaf Absorption Parameter = 0.85 Five sample points were located within tramlines in each field and their position determined using dGPS. Five 10 metre long transects were set-up, centred on each of these points and marked with coloured flags, marking the longitudinal extent of each Elementary Sampling Unit (ESU). The ‘width’ of the area sampled within the crop was determined by the reach of the instrument, around 1 metre. The geographic co-ordinates in the data file have been calculated to allow for the offset of sample measurements from the tramlines, and these should be taken as the definitive locations of the individual samples. SunScan measurements were made every metre along a 30 m transect, the central 10 m length of which coincided with the area between the coloured flags. Each of the extended ESUs was sampled in the same order in each field: Red, Green, Blue, Yellow, White flag, following a path along the tramlines shown in Figure 1. This gave a total of 165 LAI measurements per field. The geographic co-ordinates of each measurement were recorded and represented alongside the measured variables. For further details see the dataset's metadata document in linked documentation.