Martin D. Verweij
Lab. of Electromagnetic Res., Dept. of Elec. Eng., Delft Univ. of Technol., P. O. Box 5031, 2600 GA Delft, The Netherlands
The method of modeling transient acoustic waves in continuously layered media using a combination of higher-order WKBJ asymptotic representations and the Cagniard--De Hoop method is addressed. The coefficients of the WKBJ asymptotic representations satisfy a recurrence scheme, which is easily dealt with by applying symbolical manipulation. Moreover, an efficient use of the Cagniard--De Hoop method of inversion is achieved [M. D. Verweij, J. Acoust. Soc. Am. 92, 2223--2238 (1992)]. The performance of this method is discussed on the basis of numerical results for a series of configurations. In particular it is shown how the method performs if transcendental parameter profile functions are replaced by least-square-fit polynomials. From the results it is concluded that the method performs best for low-order polynomial parameter profiles.