F. David, J. C. Parrish, and . Derber, The national meteorological center's spectral statistical interpolation analysis system, Monthly Weather Review, vol.120, pp.1747-1763, 1992.

R. Todling and S. E. Cohn, Suboptimal Schemes for Atmospheric Data Assimilation Based on the Kalman Filter, Monthly Weather Review, vol.122, issue.11, pp.2530-2557, 1994.
DOI : 10.1175/1520-0493(1994)122<2530:SSFADA>2.0.CO;2

K. Ide, P. Courtier, M. Ghil, and A. C. Lorenc, Unified notation for data assimilation: operational, sequential and variational, Journal of the Meteorological Society of Japan, issue.1B, pp.75181-189, 1997.

S. M. Uppala, The ERA-40 re-analysis, Quarterly Journal of the Royal Meteorological Society, vol.132, issue.612, pp.2961-3012, 2005.
DOI : 10.1256/qj.04.176

E. Kalnay, The NCEP/NCAR 40-Year Reanalysis Project, Bulletin of the American Meteorological Society, vol.77, issue.3, pp.437-471, 1996.
DOI : 10.1175/1520-0477(1996)077<0437:TNYRP>2.0.CO;2

G. J. Huffman, The Global Precipitation Climatology Project (GPCP) Combined Precipitation Dataset, Bulletin of the American Meteorological Society, vol.78, issue.1, pp.5-20, 1997.
DOI : 10.1175/1520-0477(1997)078<0005:TGPCPG>2.0.CO;2

S. Massart, S. Buis, P. Erhard, and G. Gacon, Use of 3DVAR and Kalman filter approaches for neutronic state and parameter estimation in nuclear reactors, Nuclear Science and Engineering, vol.155, issue.3, pp.409-424, 2007.

B. Bouriquet, J. Argaud, P. Erhard, G. Gacon, S. Massart et al., Robustness of nuclear core activity reconstruction by data assimilation (submited), 2010.

O. Talagrand, Assimilation of observations, an introduction, Journal of the Meteorological Society of Japan, vol.75, issue.1B, pp.191-209, 1997.

E. Kalnay, Atmospheric Modeling, Data Assimilation and Predictability, 2003.
DOI : 10.1017/CBO9780511802270

F. Bouttier and P. Courtier, Data assimilation concepts and methods. Meteorological training course lecture series, ECMWF, 1999.

F. Rabier, H. Järvinen, E. Kilnder, J. F. Mahfouf, and A. Simmons, The ECMWF operational implementation of four-dimensional variational assimilation. I: Experimental results with simplified physics, Quarterly Journal of the Royal Meteorological Society, vol.121, issue.564, pp.1143-1170, 2000.
DOI : 10.1002/qj.49712656415

J. James, L. J. Duderstadt, and . Hamilton, Nuclear reactor analysis, 1976.

G. Matheron, La théorie des variables régionalisées et ses applications, Cahiers du Centre de Morphologie Mathématique de l'ENSMP, 1970.

D. Marcotte, Géologie et géostatistiqueminì eres (cours), 2008.