Geoacoustic tomographic inversion in shallow water

The high 3D variability (as a function of range, depth, and azimuth) of geoacoustic parameters in shallow water demands very efficient tomographic estimation methods. Most emphasis to date on geoacoustic inversion has concentrated on more straightforward 1D range independent scenarios, and even these cases have been quite difficult (as seen at the Inversion Workshop '97 and discussed in Tolstoy et al., '98). This paper discusses recent efforts to generalize a deep water 3D matched field processing tomographic method for the estimation of 3D shallow water geoacoustic parameters.