Integrated Models of Signals and Background for an HMM/Neural Net Ocean Acoustic Events Classifier
NAVAL OCEAN SYSTEMS CENTER SAN DIEGO CA
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This paper investigates the use of Hidden Markov models HMMs for the classification and detection of ocean acoustic events in a nonstationary ocean background. A statistical formalism is described for integrating models for dynamic acoustic events and ocean background into a unified statistical framework. In this framework, both signal processes and background processes are modeled as HMMs, and signal classification is performed by obtaining the likelihood of a corrupted observation sequence through a combined state space of signal and background. Techniques are presented for estimating the acoustic event model parameters from training exemplars that are observed in these difficult background conditions. Finally, a novel neural network technique is proposed for the automatic learning of the nonlinear mechanism through which signal and background observations interact. Experimental results are presented.
- Physical and Dynamic Oceanography
- Numerical Mathematics
- Acoustic Detection and Detectors