Accession Number:

ADA589865

Title:

The Effects of Internal Tides on Acoustic Propagation in the Philippine Sea

Descriptive Note:

Master's thesis

Corporate Author:

NAVAL POSTGRADUATE SCHOOL MONTEREY CA

Personal Author(s):

Report Date:

2013-09-01

Pagination or Media Count:

75.0

Abstract:

In 2009, a monthlong study was conducted in the Western Philippine Sea. This experiment collected oceanographic and acoustic data from two moorings, the Distributed Vertical Line Array DVLA and T1 moorings. The T1 mooring used a 1,095m depth source to send broadband acoustic signals to DVLA receivers located between the depths of 800m and 1,385m. Jacob A. Fischer conducted the internal tide analysis presented in Chapter II. The oceanographic data were used to quantify the characteristics of internal tides in the sample area. Spectral analysis and mode fitting, shows that most of the energy within the internal tides is due to mode 1 of the tidal frequencies. Weston R.T. Coby conducted the acoustic analysis presented in Chapter III. The acoustic data were first used to identify acoustic timefronts across the observed depths, and track the timefronts arrivals. A ray prediction model was then used to match eigenray properties to the observed timefronts. Finally the Viterbi program was used to track timefront arrivals, and intensity for statistical analysis. Weston R.T. Coby and Jacob A. Fischer jointly compared the internal tide and acoustic variability presented in Chapter IV, proving internal tides significantly impact sound speed fluctuations in the Philippine Sea.

Subject Categories:

  • Physical and Dynamic Oceanography

Distribution Statement:

APPROVED FOR PUBLIC RELEASE