activity
20172023
most citedOn the use of the saddle formulation in weakly-constrained 4D-VAR data assimilation

14 citations · 46 across the 6 of their papers we have counts for

collaborators

6 papers

eess.IV2023★ 2 cited

Dealing With Non-Gaussianity of SAR-derived Wet Surface Ratio for Flood Extent Representation Improvement

Thanh Huy Nguyen, Sophie Ricci, Andrea Piacentini +3

Owing to advances in data assimilation, notably Ensemble Kalman Filter (EnKF), flood simulation and forecast capabilities have greatly improved in recent years. The motivation of t…

eess.IV2023★ 12 cited

Gaussian Anamorphosis for Ensemble Kalman Filter Analysis of SAR-Derived Wet Surface Ratio Observations

Thanh Huy Nguyen, Sophie Ricci, Andrea Piacentini +3

Flood simulation and forecast capability have been greatly improved thanks to advances in data assimilation (DA) strategies incorporating various types of observations; many are de…

math.NA2019★ 11 cited

Exploiting variable precision in GMRES

Serge Gratton, Ehouarn Simon, David Titley-Peloquin +1

We describe how variable precision floating point arithmetic can be used in the iterative solver GMRES. We show how the precision of the inner products carried out in the algorithm…

math.NA2018★ 1 cited

Minimizing convex quadratic with variable precision conjugate gradients

S. Gratton, E. Simon, D. Titley-Peloquin +1

We investigate the method of conjugate gradients, exploiting inaccurate matrix-vector products, for the solution of convex quadratic optimization problems. Theoretical performance…

math.NA2017★ 6 cited

A note on preconditioning weighted linear least squares, with consequences for weakly-constrained variational data assimilation

Serge Gratton, Selime Gürol, Ehouarn Simon +1

The effect of preconditioning linear weighted least-squares using an approximation of the model matrix is analyzed, showing the interplay of the eigenstructures of both the model a…

math.NA2017★ 14 cited

On the use of the saddle formulation in weakly-constrained 4D-VAR data assimilation

S. Gratton, S. Gürol, E. Simon +1

This paper discusses the practical use of the saddle variational formulation for the weakly-constrained 4D-VAR method in data assimilation. It is shown that the method, in its orig…