Underwater channel modeling for sonar applications

Epçaçan, Erdal
Underwater acoustic channel models have been studied in the context of communication and sonar applications. Acoustic propagation channel in an underwater environment exhibits multipath, time-variability and Doppler e ects. In this thesis, multipath fading channel models, underwater physical properties and sound propagation characteristics are studied. An underwater channel model for sonar applications is proposed. In the proposed model, the physical characteristics of underwater environment are considered in a comprehensive manner. Experiments /simulations were carried out using real-life data. Model parameters are estimated for a specific location, scenario and physical conditions. The channel response is approximated by fitting the model output to the recorded data. The optimization and estimation are conducted in frequency domain using Mean Square Error criterion.


Topology Control Vector Based Forwarding Algorithm for Underwater Acoustic Networks
Yazgi, Ilkay; Baykal, Buyurman (2016-05-19)
The communication range of underwater acoustic networks (UAN) is limited by the properties of underwater environment. Especially, the networks including small number of nodes have communication problems for long ranges. To challenge this problem, topology control in UAN is a promising solution. In this study, Topology Control Vector Based Forwarding Algorithm (TC-VBF) is proposed. The TC-VBF uses nodes' position to determine the forwarding vector. In this work, the TC-VBF is evaluated comparatively with alt...
Response of acoustic imaging systems using convergent leaky waves to cylindrical flaws
Günalp, Nilgün; Atalar, Abdullah (Institute of Electrical and Electronics Engineers (IEEE), 1989-9)
A theoretical study of imaging systems utilizing focused leaky surface acoustic waves (SAWs), and their response to certain kind of defects is presented. In particular, circular cylindrical inhomogeneities with axes perpendicular to the surface are considered. The scattering of the SAW from this cylinder is formulated with some approximations. The surface wave incident on the inhomogeneity is initially found as an angular spectrum of plane waves. However, to apply the boundary conditions at the cylindrical ...
Performance evaluation of a new cross layer protocol for sink powered underwater acoustic sensor networks
Türken, Hasan; Bilgen, Semih; Department of Electrical and Electronics Engineering (2013)
The term Sink Powered Underwater Acoustic Sensor Networks (SPUASN) refers to a special configuration within the recent Remotely Powered Underwater Acoustic Sensor Networks (RPUASN) paradigm, where the data sink supplies energy to battery-free sensors that constitute the network. This thesis evaluates the performance of a new cross layer protocol, Cross Layer Power Adaptive CSMA/CA (X-PACCA), proposed for SPUASN. Simulation based performance evaluation is conducted both by investigating the effects of design...
Sea surface motion induced effects on high frequency underwater acoustic signals /
Güneş, Hasan; Çiloğlu, Tolga; Department of Electrical and Electronics Engineering (2014)
Acoustic signal scattering from the moving sea surface constitutes one of the most significant problems in underwater communication and sonar applications when dealing with signal processing especially at high frequencies. In this thesis, a realistic 3D linear sea surface wave model which solves governing equations is combined with a ray based computationally efficient acoustic model, BELLHOP, in order to simulate the effects of the time-evolving sea surface on acoustic waves. Rough sea surface realizations...
Self-deployment of mobile underwater acoustic sensor networks for maximized coverage and guaranteed connectivity
ŞENEL, FATİH; Akkaya, Kemal; Erol-Kantarci, Melike; Yilmaz, Turgay (2015-11-01)
Self-deployment of sensors with maximized coverage in Underwater Acoustic Sensor Networks (UWASNs) is challenging due to difficulty of access to 3-D underwater environments. The problem is further compounded if the connectivity of the final network is desired. One possible approach to this problem is to drop the sensors on the water surface and then move them to certain depths in the water to maximize the 3-0 coverage while maintaining the initial connectivity. In this paper, we propose a fully distributed ...
Citation Formats
E. Epçaçan, “Underwater channel modeling for sonar applications,” M.S. - Master of Science, Middle East Technical University, 2011.