Improved estimates of vegetation biophysical variables from MERIS TOA images by using spatial and temporal constraints

Claire Lauvernet Frédéric Barret Laurent Hascoët Francois-Xavier Le Dimet

Proceedings of the 9th International symposium on Physical measurements and signatures in remote sensing, ISPMSRS 2005, Beijing, China (3 pages)

Abstract: A new method for estimating canopy biophysical variables from the satellite observations is developed based on a variational assimilation technique. This allows accounting for the spatial and temporal constraints in the estimation process of crop characteristics. Inversion will be achieved concurrently over an ensemble of pixels belonging to a spatial and temporal window. This ensures the problem to be better posed than when solved over single pixels and dates. Atmospheric characteristics are assumed steady within the spatial window, but vary from date to date. Conversely, surface characteristics are assumed to be steady within the limited temporal window, but spatially variable. This paper explains the variational assimilation theory used here, the surface and atmosphere radiative transfer models considered, and the ensemble assimilation scheme applied to account for the spatial and temporal constraints.

Keywords: Automatic Differentiation, Adjoint code, Variational Data Assimilation Satellite observations, Agronomics

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@inproceedings{LBHL05,
  author = {Lauvernet, C. and Baret, F. and Hasco\"et, L. and LeDimet, F.-X.},
  title = {Improved estimates of vegetation biophysical variables
        from MERIS TOA images by using spatial and temporal constraints},
  booktitle = {proceedings of the 9th International symposium on
      Physical measurements and signatures in remote sensing, ISPMSRS 2005,
      Beijing, China},
  year = 2005
}