The Network for Calibration and Validation of Earth Observation data (NCAVEO) organised a field experiment in the summer of 2006 based around the Chilbolton Facility for Atmospheric and Radio Research.

The aim of the experiment is designed to test the accuracy of satellite techniques for measuring environmental characteristics and will facilitate knowledge transfer between academic researchers, remote sensing data providers and users of Earth observation data in government and industry.

The focus of the experiment was from the 12th-23rd June 2006, when data was acquired from a range of aircraft and satellite sensors, including imaging spectrometers, lidars and digital cameras. Teams of researchers were on the ground during this period, measuring properties of the vegetation such as the leaf area index of agricultural crops and forest stands.

The instruments based at Chilbolton provided detailed information on the state of the atmosphere. In particular the sunphotometer provided aerosol optical depth, and the ceilometer gives information on the cloud cover. This data is important as it allows atmospheric corrections to be applied to the Earth observation data.

As shown in the image below, three tarpaulin calibration targets were used as ground based targets on the 500m range at the Observatory, to calibrate the data from aircraft and satellite sensors. Alongside the tarpaulins were two instruments making spectral reflectance measurements for later comparison with the airborne and satellite EO data.

After the event, Prof. Ted Milton the NCAVEO co-ordinator commented that "56 people, 4 aircraft, 5 satellites and 6 international visitors were involved over 10 days to conduct the NCAVEO 2006 Field Experiment at Chilbolton, Hampshire. Early indications suggest that we have a complete set of ground, airborne and satellite data from the 'Golden Day', Saturday 17th June, and many other partial data sets with which to tackle specific research questions"