A method that formulates the retrieval of drop size distribution (DSD) parameters from polarimetric radar variables at attenuating frequency as the solution of an inverse problem is presented. The DSD in each radar bin is represented by a normalized Gamma distribution defined by three parameters (Dm,N0*,μ). The direct problem that describes polarim...
International audience
Monitoring the small variations of a medium is increasingly important in subsurface geophysics due to climate change. Classical seismic surface wave dispersion methods are limited to quantitative estimations of these small variations when the variation ratio is smaller than 10 per cent, especially in the case of variations in deep media. Based on t...
La gestion de la ville et des territoires est une tâche complexe nécessitant de multiples compétences dans des domaines très variés. Au cours de ce XXIème siècle, la ville et les territoires doivent faire face à des enjeux majeurs sur le plan environnemental et sociétal : la rareté de l'eau, le réchauffement climatique, la qualité de l'air et bien ...
La gestion de la ville et des territoires est une tâche complexe nécessitant de multiples compétences dans des domaines très variés. Au cours de ce XXIème siècle, la ville et les territoires doivent faire face à des enjeux majeurs sur le plan environnemental et sociétal : la rareté de l'eau, le réchauffement climatique, la qualité de l'air et bien ...
The first meters of the underground media, the Critical Zone, involve many human activities. It is also the site of disturbances due to climate change through variations in the level of the water table, hydric and mechanical modifications that increase erosion and the risks of damage or even collapse. Therefore, monitoring of the subsurface and its...
La détection précoce des pathologies rétiniennes chez l’Homme réclame des moyens d’imagerie in vivo non invasifs du tissu rétinien, à l’échelle de la cellule. Or, l’observation de la rétine depuis l’extérieur souffre de la mauvaise qualité optique de l’œil, des mouvements oculaires, de la diffusion de la lumière par les tissus, et du mauvais rappor...
Impact identification is a major concern in structural health monitoring. It consists in localizing the impact point and in reconstructing the applied load history from indirect measurements. However, it is well-known that this double inverse problem is ill-posed. In this paper, a single-sensor approach for quickly localizing a Dirac-like impact an...
A new identification technique is proposed to evaluate the tension of a cable using a static inverse approach that couples a universal cable model with displacement sensors, strain gauges and added masses that should preserve operational affordability. An inverse problem is formulated as the minimization of a data misfit functional based on the dif...
This study presents a novel strategy for identifying an impact event on a structure from vibration measurements. Compared to triangulation techniques that require at least three sensors on a plate-like structure, only one sensor is used in this work for localizing the impact point. The proposed approach consists in extracting specific modal pondera...
