ASYMPTOTIC ANALYSIS OF ACOUSTIC GREEN'S FUNCTIONS.

An asymptotic expansion of layered Green's function is examination in a spatial domain and parametric approach is proposed by determining a small parameter to derive the shortened form of Green's function for 3- and 4-layered structures. For qualitative testing and comparison of the exact Green's function and asymptotic shortened Green's functions associated with the measurement and source point in the same layer, we performed numerical calculations. [ABSTRACT FROM AUTHOR]