It is well known that geoacoustic inversion in shallow water is difficult - even for a single, range-independent slice between a source and receiver array. This paper will discuss simulated results which show the application of a tomographic inversion method over a number of quite variable areas (each of which involves over 100 range-dependent slices) to determine water depth. The final tomographic (matrix) inversions giving the 3-D range dependence are extraordinarily simple, fast, and accurate - more so than for the inversion of an individual path. However, the overall quality of the results depends on the preliminary inversion accuracies (individual slices) which in turn depend on array parameters (how many phones, how densely packed, where distributed), source parameters (frequencies and distribution), and on the geoacoustic parameters to be determined (here we consider only water depth). Additionally, adiabatic normal modes have been assumed for the derivation of the method but are not required for its application. The implications for this approach include an ability to rapidly and non-invasively estimate bottom parameters over a 3-D area of interest.
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