STUDY OF HIGH-FREQUENCY ECHOGRAMS OF HETEROGENEOUS MEDIA USING DECONVOLUTION TECHNIQUES

The aim of this work is to improve the localization properties for het erogeneities available from high frequency ultrasonic echograms, and t hus the on-axis spatial resolution. For this purpose, a simple inverse filtering technique is considered and matched to our specific needs. The theoretical and experimental results obtained for water suspension s of small moving scatterers (in the 10-80 mum range) and for metal ma trix composites (SiC reinforced) are reported. The modelling for the a rtificial heterogeneous medium and its validation for real heterogeneo us materials will enable, after some refinements, the development of b iological cell counting techniques in the near future.