Le mardi 23 septembre 2025, Joachim BALIS présentera l'examen en vue de l’obtention du grade académique de Docteur en Sciences (Collège de doctorat en Sciences spatiales) sous la direction d'Emmanuel JEHIN et Hervé LAMY.
Cette épreuve consistera en la défense publique d’une dissertation intitulée :
« Towards a better understanding of the meteoroid complex using forward scatter radio observations of the BRAMS network ».
Le Jury sera composé de :
M. D. GRODENT (Président), MM. P. BROWN (University of Western Ontario), J. DE KEYSER (Royal Belgian Institute for Space Aeronomy), B. HUBERT (Secrétaire), E. JEHIN (Promoteur), J. KERO (Swedish Institute of Space Physics), H. LAMY (Royal Belgian Institute for Space Aeronomy) (Co-promoteur).
Every day, millions of meteoroids enter Earth’s atmosphere. Studying them provides valuable insights into the distribution and properties of dust and small bodies in the Solar System, the dynamics of the upper atmosphere, and the influx of extraterrestrial material to Earth. Their very high speeds also pose a significant threat to spacecraft.
This thesis explores how forward scatter continuous wave radio observations can be used to reconstruct meteoroid trajectories and speeds. The work is based on data from the Belgian RAdio Meteor Stations (BRAMS) network. BRAMS offers several advantages over traditional radars, including wider detection coverage, higher sensitivity, and lower cost.
Results demonstrate that BRAMS can effectively contribute to the systematic retrieval of meteoroid trajectories and speeds. This work paves the way for characterizing smaller and higher-altitude objects inaccessible to optical systems, enhancing our understanding of the meteoroid complex.
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La thèse est intitulée : « Multi-scale assessment of the biological and ecological responses of Posidonia oceanica to transplantation for the optimization of seagrass meadow restoration ».
La thèse est intitulée : « Impact of bathymetric thresholds on the hydrodynamic circulation in a micro-tidal setting and on the sedimentary processes in a semi-enclosed basin : case of the Corinth Gulf (Greece) ».
La thèse est intitulée : « Multiscale hydrodynamic modelling of the Danube Delta ».
La thèse est intitulée : « Emissions of CO2, CH4, and N2O from urban ponds of the city of Brussels ».
La thèse est intitulée : « Unveiling the Ecological Strategies of Streptomyces scabiei: Virulence, Competition and Nutrient Adaptation ».
