ASA 124th Meeting New Orleans 1992 October

4aUW10. Developments in phase-matching filter techniques.

G. Orris

B. E. McDonald

W. Kuperman

Naval Res. Lab., Washington, DC 20375-5000

For low signal-to-noise (S/N) data, an algorithm has been reported that is very effective when the shape of the noise spectrum is known and smooth as a function of frequency. The method uses the phases of the spectral components as free parameters in a variational problem. Improvements on the basic method to help relax the idealistic assumptions made have been investigated. Methods employing empirical orthogonal functions (EOFs) to exploit further degrees of freedom in the solution are presented. For cases of moderate S/N, an algorithm is presented that attempts to utilize signal-free intervals in improving S/N.