Vegetation fiducial reference test sites for satellite product validation
Satellites are used extensively to monitor properties of the Earth’s vegetation, offering an effective way to obtain frequent, global measurements where ground-based measurements are not practical. Applications of these measurements range from climate, environmental and ecological monitoring, agriculture, forestry and land management.
Ideally, information derived from satellites should be validated against reference measurements (either in situ or airborne) of the same quantity, which are traceable to SI and whose uncertainties are well characterised.
Traceable end-to-end quality assessment of satellite products, that includes uncertainty characterisation of the retrieval algorithm as well as the reference (in situ or airborne) data and methods used to validate the algorithm, is critical for understanding the derived information, as well as the nuances between the wealth of similar satellite derived products that are currently available.
NPL have been working at Wytham Woods site in Oxford, UK to develop and test the methods which should be followed by the international validation community when:
- collecting campaign and permanent fiducial reference measurements, and
- performing validation of satellite derived products, over the vegetated land surface.
This work aims to establish Wytham Woods as one of a network of global CEOS (Committee on Earth Observation Satellites) 'supersites' for Earth observation calibration and validation.