Source/Receiver Motion-Induced Doppler Influence on the Bandwidth of Sinusoidal Signals
Abstract
Most self-propelled vessels moving on, or under, the ocean surface, contain rotating machinery that radiate finite bandwidth signals into the water. Empirical evidence suggests that the signal bandwidth estimated with a far field receiver is often greater than expected. This thesis investigates the use of an acoustic propagation model to predict the received bandwidth of sinusoidal signals when both the source and the receiver are in motion. The bandwidth parameter is calculated from the multi-frequency transmission loss (TL) predicted with a re-written version of K. Smith's Monterey-Miami Parabolic Equation (MMPE) model, including both receiver and source motion. The results for various propagation environments allow exploration of the characteristics of received bandwidth, predicted from sources on the surface or at depth. The dependency of aggregate bandwidth upon conditional parameters such as range, depth, and normalized pressure are also evaluated. In addition to modeling results, this thesis documents a new implementation of the MMPE model for narrowband signals using only the MATLAB programming language. A MATLAB version has the inherent advantages of increased flexibility and portability. A MATLAB implementation of a range dependent ray trace function based upon a Runge-Kutta integration of the eikonal equations is also presented.
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 01, 2003
- Accession Number
- ADA420613
Entities
People
- David J. Pistacchio
Organizations
- Naval Postgraduate School