Statistical Analysis of Acoustic Signal Propagating Through the South China Sea Basin
Abstract
During the Windy Islands Soliton Experiment, two deep water moorings were deployed 167 km a part in the northeastern South China Sea (SCS) basin to study the effects of nonlinear internal waves on 400-Hz acoustic signal propagation. The acoustic arrival structure for this path shows five significant arrivals, exhibiting multi-scale variability in travel time and intensity. Time series of moored temperature data, travel time of the first and a late arrival, as well as measured sound intensity were constructed. By analyzing the power spectral density of those time series, six internal tidal constituents were identified, with strong diurnal and semidiurnal energy. The variances in the temperature and travel time were dominated by the internal tides, while the largest variance in signal intensity was in the high-frequency internal-wave band. Coherence analysis of the temperature and travel times indicated that the travel time variance in the tidal band was more related to the temperature fluctuation in the west of the SCS basin. The observed standard deviations of signal intensity level were plotted against the number of independent arrivals, showing that the relation converges to a modified statistical theory of phase-random multipaths.
Document Details
- Document Type
- Technical Report
- Publication Date
- Mar 01, 2016
- Accession Number
- AD1027187
Entities
People
- Meihuei Chen
Organizations
- Naval Postgraduate School