Nombre de documents

28

CV de Julien Brajard


My work is in the field of remote sensing, inverse modelling, machine learning and data assimilation.

The objective is to propose new methodologies in order to extract knowledge from data and physical systems, 

more specifically in oceanography.

 

Those methodologies were apply to estimate and forecast key variables and their associated uncertainty in the ocean such as 

phytoplankton and surface currents. The methodologies developed were

using remote sensing data (satellite sensors).

 

Key words : Machine learning, statistical methods, remotesensing, oceanography, computer science


Article dans une revue12 documents

  • Hector Simon Benavides Pinjosovsky, Sylvie Thiria, Catherine Ottlé, Julien Brajard, Fouad Badran, et al.. Variational assimilation of land surface temperature within the ORCHIDEE Land Surface Model Version 1.2.6. Geoscientific Model Development, European Geosciences Union, 2017, 10 (1), pp.85-104. <10.5194/gmd-10-85-2017>. <hal-01492602>
  • Leila Issa, Julien Brajard, Milad Fakhri, Daniel Hayes, Laurent Mortier, et al.. Modelling surface currents in the Eastern Levantine Mediterranean using surface drifters and satellite altimetry. Ocean Modelling, Elsevier, 2016, 104, pp.1-14. <10.1016/j.ocemod.2016.05.006>. <hal-01357669>
  • Ousmane Farikou, Salam Sawadogo, Awa Niang, Daouda Diouf, Julien Brajard, et al.. Inferring the seasonal evolution of phytoplankton groups in the Senegalo-Mauritanian upwelling region from satellite ocean-color spectral measurements. Journal of Geophysical Research. Oceans, Wiley-Blackwell, 2015, 120 (9), pp.6581--6601. <10.1002/2015JC010738>. <hal-01507522>
  • Pacôme Eberhart, Julien Brajard, Pierre Fortin, Fabienne Jézéquel. High Performance Numerical Validation using Stochastic Arithmetic . Reliable Computing, Springer Verlag, 2015, 21, pp.35-52. <hal-01254446>
  • D. Diouf, Awa Niang, Julien Brajard, Michel Crépon, Sylvie Thiria. Retrieving aerosol characteristics and sea-surface chlorophyll from satellite ocean color multi-spectral sensors using a neural-variational method. Remote Sensing of Environment, Elsevier, 2013, 130, pp.74 - 86. <10.1016/j.rse.2012.11.002>. <hal-01495282>
  • Julien Brajard, Richard Santer, Michel Crépon, Sylvie Thiria. Atmospheric correction of MERIS data for case-2 waters using a neuro-variational inversion. Remote Sensing of Environment, Elsevier, 2012, 126, pp.51 - 61. <10.1016/j.rse.2012.07.004>. <hal-01495015>
  • Julien Brajard, Cyril Moulin, Sylvie Thiria. Atmospheric correction of SeaWiFS ocean color imagery in the presence of absorbing aerosols off the Indian coast using a neuro-variational method. Geophysical Research Letters, American Geophysical Union, 2008, 35, pp.20604. <10.1029/2008GL035179>. <hal-00752788>
  • Fouad Badran, Mohamed Berrada, Julien Brajard, Michel Crépon, Charles Sorror, et al.. Inversion of satellite ocean colour imagery and geoacoustic characterization of seabed properties: Variational data inversion using a semi-automatic adjoint approach. Journal of Marine Systems, Elsevier, 2008, 69 (1-2), pp.126--136. <10.1016/j.jmarsys.2007.02.018>. <hal-01507523>
  • Julien Brajard, Awa Niang, Salam Sawadogo, Frank Fell, Richard Santer, et al.. Estimating aerosol parameters above the ocean from MERIS observations using topological maps. International Journal of Remote Sensing, Taylor & Francis, 2007, 28 (3-4), pp.781--795. <hal-01507524>
  • Julien Brajard, Awa Niang, S. Sawadogo, F. Fell, R. Santer, et al.. Estimating Aerosol parameters from MERIS ocean colour sensor observations by using topological maps. International Journal of Remote Sensing, Taylor & Francis, 2006, 28 (3-4), pp.781-795. <10.1080/01431160600821101>. <hal-00750293>
  • Julien Brajard, Cédric Jamet, Cyril Moulin, Sylvie Thiria. Use of a neuro-variational inversion for retrieving oceanic and atmospheric constituents from satellite ocean colour sensor: Application to absorbing aerosols. Neural Networks, Elsevier, 2006, 19, pp.178-185. <10.1016/j.neunet.2006.01.015>. <hal-00122477>
  • Julien Brajard, Cédric Jamet, Cyril Moulin, Sylvie Thiria. Validation of a neuro-variational inversion of ocean colour images. Advances in Space Research, Elsevier, 2006, 38 (10), pp.2169-2175. <10.1016/j.asr.2006.03.039>. <hal-00750296>

Communication dans un congrès13 documents

  • Julien Brajard, Anastase Alexandre Charantonis, F. Jourdin. Predicting Ocean Dynamics through Machine Learning: Application on Sea-Surface Suspended Particulate Mater. American Meteorological Society Annual Meeting 2017, Jan 2017, Seattle, United States. <https://ams.confex.com/ams/97Annual/webprogram/Paper313041.html>. <hal-01477182>
  • Julien Brajard, Jérôme Sirven, Olivier Talagrand. Ensemble variational data assimilation with a shallow-water model: preliminary results. EGU General Assembly, Apr 2016, Vienne, Austria. 18, pp.14836, 2016, <http://meetingorganizer.copernicus.org/EGU2016/EGU2016-14836-1.pdf>. <hal-01507519>
  • Pacôme Eberhart, Julien Brajard, Pierre Fortin, Fabienne Jézéquel. Estimation of Round-off Errors in OpenMP Codes. IWOMP 2016 - 12th International Workshop on OpenMP, Oct 2016, Nara, Japan. Springer International Publishing, 9903, pp.3-16, 2016, Lecture Notes in Computer Science. <10.1007/978-3-319-45550-1_1>. <hal-01380131>
  • Yala Khalil, Julien Brajard, Michel Crépon, Éric Machu, Ndèye Niang. Determination of phytoplankton groups from space: application to senegalo-mauritanean upwelling. EGU General Assembly, 2016, Vienne, Austria. 18, pp.15098, 2016, <http://meetingorganizer.copernicus.org/EGU2016/EGU2016-15098.pdf>. <hal-01507521>
  • Ymane Taoufiq, Ousmane Farikon, Séverine Alvain, Julien Brajard, Michel Crépon, et al.. Determination of phytoplankton groups from ocean color spectral measurements in the Senegalo-Mauritanian upwelling. Ocean Optics, Oct 2014, Portland, Maine, United States. Ocean Optics, 2014, <http://www.tos.org/oceanoptics2014/>. <hal-01191676>
  • Pacôme Eberhart, Julien Brajard, Pierre Fortin, Fabienne Jézéquel. Towards high performance stochastic arithmetic. 16th international symposium on Scientific Computing, Computer Arithmetic and Validated Numerics (SCAN 2014), Sep 2014, Würzburg, Germany. pp.47-48. <hal-01217244>
  • Julien Brajard, Pei Li, Fabienne Jézéquel, Hector-Simon Benavidès, Sylvie Thiria. Numerical Validation of Data Assimilation Codes Generated by the YAO Software. SIAM Annual Meeting, Jul 2013, San Diego, California, United States. <hal-01216453>
  • Julien Brajard, Doauda Diouf, Hector Simon Benavides Pinjosovsky, Michel Crépon, R. Santer, et al.. Neuro-Variational Inversion Applied to Ocean Color Remote Sensing. American Meteorological Society Annual Meeting, 2012, La Nouvelle Orléans, United States. <hal-00750316>
  • Doauda Diouf, Julien Brajard, Awa Niang, Salam Sawadogo, Michel Crépon, et al.. Atmospheric correction and chlorophyll-a restitution in presence of Saharan dusts. Congrès European Geophysical Union, 2011, Vienne, Austria. <hal-00750241>
  • Anastase Alexandre Charantonis, Sylvie Thiria, Cyril Moulin, Julien Brajard. Inversion of sea surface data to retrieve the vertical distribution of phytoplankton using a statistical methodology. Congrès European Geophysical Union, 2011, Vienne, Austria. <hal-00750248>
  • Mohamed Berrada, Julien Brajard, Charles Deltel, Michel Crépon, Fouad Badran, et al.. Variational data assimilation in NEMO using YAO. Congrès European Geophysical Union, 2011, Vienne, Austria. <hal-00750253>
  • Anastase Alexandre Charantonis, Julien Brajard, Cyril Moulin, Fouad Badran, Sylvie Thiria. Inverse method for the retrieval of ocean vertical profiles using self-organizing maps and hidden Markov models - Application on Ocean Colour Satellite Image Inversion. NCTA 2011 : NCTA- International Conference on Neural Computation Theory and Applications, 2011, Paris, France. <hal-00750300>
  • Doauda Diouf, Sylvie Thiria, Awa Niang, Julien Brajard, Michel Crépon. Retrieving aerosol characteristics from satellite ocean color multi-spectral sensors using a neural-variational method. NCTA 2011 : NCTA- International Conference on Neural Computation Theory and Applications, 2011, Paris, France. <hal-00750307>

Poster1 document

  • Leila Issa, Julien Brajard, Milad Fakhri, Laurent Mortier, Pierre-Marie Poulain. Modeling Surface Currents in the Eastern Levantine Mediterranean. EGU General Assembly Conference, Apr 2015, Vienna, Austria. 17, pp.8888. <hal-01191755>

Chapitre d'ouvrage1 document

  • Daouda Diouf, Awa Niang, Julien Brajard, Salam Sawadogo, Michel Crépon, et al.. Spatial Distribution of Aerosol Optical Thickness Retrieved from SeaWiFS Images by a Neural Network Inversion over the West African Coast. Aerosols-Science and Case Studies, InTech, 2016, 978-953-51-2843-4. <10.5772/65874 >. <hal-01507520>

Pré-publication, Document de travail1 document

  • Luigi Nardi, Julien Brajard, Sylvie Thiria, Fouad Badran, Pierre Fortin. Automatic generation of parallel and coherent code using the YAO variational data assimilation framework. 2016. <hal-00783328v2>