George B. Smith
Naval Res. Lab., Code 7173, Stennis Space Center, MS 39529-5004
Murty A. Akundi
Xavier Univ. of Louisiana, New Orleans, LA 70124
In this work the environmental mismatch problem in matched-field processing is addressed by attempting to obtain analytic expressions for mismatch-induced range localization error and signal gain degradation for a linear (replica correlator) matched-field processor using simple models such as the rigid and Pekeris waveguides. This analysis is based on the concept that these types of errors are the result of mismatch-induced dephasing of the modally interfering components of the acoustic field in the waveguide. As these modal components dephase, the signal peak degrades, and it forms at a location slightly different from the correct location. In particular, which types of mismatch produce a substantial range localization error have been determined and the frequency dependence of such range shifts has been studied. The analytic results have been substantiated with computer simulations. [This work was supported by the Office of Naval Research, Program Element 61153N, with technical management provided by the Naval Research Laboratory, Stennis Space Center, MS.]