Objectives

Biospec will contribute to the development/improvement of remote sensing products for the estimation of biophysical parameters of Mediterranean vegetation in the context of global change. The initial hypothesis is that there is a need for accurate information on vegetation parameters for different environmental applications (including the estimation of global patterns of surface-atmosphere fluxes) and at varied spatial scales. Ecosystem process models that simulate carbon, water, and energy exchange between terrestrial ecosystems and the atmosphere require the estimation of biophysical vegetation parameters, and these can be derived by remote sensing. However, a number of factors make the quantification of these parameters a difficult task. This project deals with some of these factors:

• Sampling scale (scale mismatch between biophysical and flux measurements and remote sensing data). A scaling-up process is proposed in order to properly link spectral information and biophysical parameters from small objects (leaves) to pixels and finally to composite scenes (vegetation canopies) using laboratory and field spectroscopy, airborne hyperspectral images and multispectral satellite data.
  

• Robustness of the relationships between spectral response and fluxes (varying efficiency of reflectance indices due to variable illumination and environmental conditions). Quantitative analysis of the relative importance of these factors in the estimation of the vegetation parameters will allow to test the different methods proposed. Remote sensing provides spatial information on the biophysical parameters in relation to water, carbon and energy cycles to calibrate Mediterranean ecosystems in the context of an existent global network.

• Accuracy of satellite derived products. The project will emphasize the analysis and quantification of the uncertainty associated to the multi-scale estimation of the vegetation parameters.