T. C. Yang
Naval Res. Lab., Washington, DC 20375
Vector Res. Co., Rockville, MD 20852
Acoustic inversion of geoacoustic properties in the ocean bottom has been investigated recently using matched-field processing. In the shallow Arctic waters, the acoustic signal may still be dominated by waterborne modes. As a consequence, the matched-field correlation may not be very sensitive to bottom sound-speed variation. It is found that in a water depth of approximately 600 m the matched-field correlation remains very high (>0.95) even with a mismatch of 50 m/s in bottom sound-speed profile. To improve the sensitivity to bottom mismatch, we include only the high-order modes in the matched-field/mode correlation. This method is investigated using a simulated broadband signal and also using SUS data received on a vertical array. The source is localized using broadband matched-field/mode processing. Short-range data are considered to maximize bottom interacting signals.