The characteristics of an insonified object are generally present in the signal carried by the returning scattered wave. Because an echo contains only a partial result of the wave interaction with a material structure, the inverse acoustical scattering process is an ill‐posed mathematical problem that may not have unique solutions. However, by decomposing the normalized echo signature (the form function), certain features that appear in the joint time and frequency domains can be exploited to relate the scatterer's acoustical signature to its structural response. The approach of the form function decomposition is based on the frequency domain Wigner distribution function formulation. A computer algorithm extended from image processing techniques is then implemented to depict the numerical results in a two.dimensional (tvs ω) display. From the interpretation and understanding of scattering phenomenon, the physical parameters of the scatterer can be extracted from the graphical representation. Examples from numerically simulated models and laboratory measurements are illustrated for estimating the general physical size and the corresponding elastic properties of the insonified object.