Antoine Richard's doctoral dissertation entitled 'Characterization of acoustic properties of surfaces based on spatio-temporal information' develops methods to characterize sound absorption and scattering properties of surface materials used e.g. in room acoustics. This is a very well written dissertation that addresses an important and timely topic in a rigorous manner, since the limited availability of these properties for surfaces remains a limiting factor in room acoustic modelling.
Effort is given to in-situ capability of the methods and the work is verified by numerical tests and further validated through experimental investigations. It contains a reasonable balance of mathematical analysis, numerical simulation and experimental measurements. The dissertation contains several novel achievements - each of these are appropriately segregated into three archival peer-reviewed submissions and one report. These dissemination documents are well developed and comprise the bulk of the dissertation:
A: Measurement of angle-dependent absorption using a spherical near-field acoustic holographic array.
B: Comparison of planar and spherical array geometries for surface impedance estimation.
C: Estimation of scattering from pressure and particle velocity measurements over an enclosing surface.
D: Characterization of far-field scattering by considering only the front surface of a finite scatterer.
Antoine gave a very clear and excellent presentation and he answered all questions in a very satisfying manner, demonstrating genuine and deep understanding of the subject matter.
Congratulations to Antoine.