Ray and Wave Chaos in Ocean Acoustics

Book excerpt: 1. Ray and wave propagation. 1.1. Underwater sound channel. 1.2. Basic equations. 1.3. Geometrical optics approximations and optical-mechanical analogy. The Hamiltonian formalism. 1.4. Ray travel times. 1.5. Range-dependent environments. 1.6. Acoustic ocean tomography. 1.7. Experiments on long-range sound propagation. 1.8. Summary -- 2. Ray chaos. 2.1. Hamiltonian chaos. 2.2. Lyapunov instability. 2.3. Ray-medium resonance. 2.4. Overlapping of resonances. 2.5. Vertical resonance. 2.6. Manifestation of regular and chaotic ray motion in distributions of ray travel times. 2.7. Summary -- 3. Wave chaos. 3.1. The problem of wave chaos. 3.2. Normal modes. 3.3. Mode coupling under chaotic conditions. 3.4. Influence of fine-scale inhomogeneities on wave dynamics. 3.5. Summary -- 4. Chaotic phenomena in random environment. 4.1. Ray chaos in a random medium. 4.2. Travel times of chaotic rays. 4.3. Modal structure of the sound field in a waveguide with random inhomogeneities. 4.4. Wave beam in an ocean acoustic waveguide. 4.5. Arrival times of sound pulses in the presence of internal waves and a mesoscale inhomogeneity. 4.6. Summary -- 5. Glossary of some concepts and notations in Hamiltonian chaos theory