ASA 130th Meeting - St. Louis, MO - 1995 Nov 27 .. Dec 01

4aUW4. Characterizing parameter landscapes for poroelastic media.

Joseph F. Lingevitch

Michael D. Collins

Naval Res. Lab., Washington, DC 20375

There is presently a great deal of interest in modeling ocean sediments as poroelastic media. One of the topics of particular interest is matched-field inversion for sediment parameters. This paper will investigate the resolvability of poroelastic parameters in ocean sediments using acoustic sources and receivers located in the water column. The eigenvectors and eigenvalues of the covariance matrix of the gradient of the cost function indicate the most important underlying parameters as well as the degree of coupling between parameters [M. D. Collins and L. Fishman, ``Efficient navigation of parameter landscapes,'' J. Acoust. Soc. Am. 98, 1637--1644 (1995)]. This information is useful for designing effective experiments for resolving the desired parameters. The information in the covariance matrix can be used to determine the most effective frequencies and array configuration and to optimize the performance of the inversion at each frequency. Wave-number integration and parabolic equation models are available for solving the forward problem [M. D. Collins, W. A. Kuperman, and W. L. Siegmann, ``A parabolic equation for poro-elastic media,'' J. Acoust. Soc. Am. 98, 1645--1656 (1995)].