A UNIFIED FRAMEWORK FOR MODE FILTERING AND THE MAXIMUM A-POSTERIORI MODE FILTER

A unified framework is presented for examining the performance of line ar mode filtering algorithms. Two common mode filters, samples of the mode shapes and the pseudo-inverse of the mode shapes, are presented i n this framework as a tradeoff between sensitivity to other modes and sensitivity to white noise. The maximum a posteriori mode filter is pr esented as an alternative which gracefully transitions between these e xtremes, and attains the minimum mean squared error when the modes to be estimated are well modeled as samples of a Gaussian random process. Numerical simulations in bath shallow and deep water environments con firm the analytically derived properties of these mode filters. (C) 19 98 Acoustical Society of America.