The development of novel marine communications channel models using theoretically-based and numerical electromagnetic simulation methods

• Main Author: Timmins, Ian
• Format: Thesis
• Language: English
• Published: Memorial University of Newfoundland 2010
• Subjects: North Atlantic
• Online Access: https://research.library.mun.ca/8976/; https://research.library.mun.ca/8976/1/Timmins_Ian.pdf

Maritime communications is fast becoming a growing area of interest. Use of a "commercial-off-the-shelf" (COTS) integration approach to system design, increasing interest in maritime security and demanding bandwidth requirements of sensors make understanding the effects of the sea on the communications channel an important design consideration when developing reliable and high bandwidth communications links. Conventional VHF communications are being replaced with SATCOM and cellular technologies for a variety of vehicular, sensor, life craft, and survival suit systems. Considering this occurrence, the marine communications channel and the effects of the sea surface have remained an area of limited study, particularly in comparison to the efforts placed on research for terrestrially-based communications channels. Urban environments, mountainous terrain, seasonal issues, and foliage are well studied in regard to effects on communications channels. To support design of systems for marine applications, the contribution of this research effort is the development of communications channel models by novel theoretical and numerical methodologies. The results of these efforts are models suitable for use in quantifying sea surface shadowing effects on communication channel performance in fully developed deep sea locations. -- First, a theoretically-based marine geometrical theory of diffraction (Marine GTD) model is developed, whereby a diffraction methodology is devised specifically for single sea surface waves. For this segment, a sea surface wave is considered as an obstructing object between transmitter and receiver creating a shadowing condition. The physical sea surface attributes are studied using the modified Pierson-Moskowitz model for the north North Atlantic such that a novel Geometrical Theory of Diffraction wedge is synthesized based exclusively upon sea surface height. The wedge is thus physically representative of a fully-developed deep sea surface wave, and may be used to estimate diffraction loss. ...