Understanding vegetation response to climate variability from space: recent advances towards the SPECTRA mission

Measurements of the rate of increase of atmospheric CO2 and calculations of the global CO2 budgets imply that a large fraction of emissions is being absorbed in terrestrial carbon pools and that current estimates put the biosphere sink at roughly about half the emissions. The SPECTRA mission adresses these issues by providing detailed observations to help understanding the terrestrial component of the carbon cycle. Scientific preparations for SPECTRA are pursued along two avenues: a) the nature of the expected data and candidate algorithms are evaluated by generating and using synthetic hyper-spectral multi-angular radiometric data; b) algorithms are evaluated with actual hyper-spectral data colelcted with a variety of airborne systems and concurrent ground measurements.