Retrieval of vegetation properties from combined hyperspectral/multiangular optical measurements: results from the DAISEX campaigns

Quantitative vegetation monitoring by means of remote sensing methods, beyond simple spectral indices, is an objective for the next generation of satellite systems, such as the ESA Earth Explorer Core Mission candidate SPECTRA (Surface Processes and Ecosystem Changes Through Response Analysis). In order to derive and validate methods for retrieval of biophysical information, and in particular vegetation properties from hyperspectral / multiangular measurements, a series of campaigns genetically called DAISEX (Digital Airborne Imaging Spectrometer Experiment) were carried out in La Mancha, Spain, from 1998-2000. A combination of aircrafts carrying different sensors and flying in different configurations allowed to get a complete dataset of hyperspectral and multiangular data acquired simultaneously, together with the necessary atmospheric information and ground data needed for validation of biophysical retrievals. A two-years study funded by ESA has exploited in depth the DAISEX dataset to evaluate the accuracy achieved in the retrieval of each one of the different vegetation properties, by using different methods applied over the same dataset. The results have shown potentials and limitations, but have allowed to set accuracy limits realistically achievable and to set more precise requirements for future developments.