title: Weakly dispersive modal pulse propagation in the North Pacific Ocean.
abstract: The propagation of weakly dispersive modal pulses is investigated using data collected during the 2004 long-range ocean acoustic propagation experiment (LOAPEX). Weakly dispersive modal pulses are characterized by weak dispersion- and scattering-induced pulse broadening; such modal pulses experience minimal propagation-induced distortion and are thus well suited to communications applications. In the LOAPEX environment modes 1, 2, and 3 are approximately weakly dispersive. Using LOAPEX observations it is shown that, by extracting the energy carried by a weakly dispersive modal pulse, a transmitted communications signal can be recovered without performing channel equalization at ranges as long as 500 km; at that range a majority of mode 1 receptions have bit error rates (BERs) less than 10%, and 6.5% of mode 1 receptions have no errors. BERs are estimated for low order modes and compared with measurements of signal-to-noise ratio (SNR) and modal pulse spread. Generally, it is observed that larger modal pulse spread and lower SNR result in larger BERs.
authors.affiliation: Applied Ocean Physics and Engineering Department, Woods Hole Oceanographic Institution, Woods Hole, Massachusetts 02543.
authors.forename: Ilya A
authors.initials: IA
authors.lastname: Udovydchenkov
authors.forename: Michael G
authors.initials: MG
authors.lastname: Brown
authors.forename: Timothy F
authors.initials: TF
authors.lastname: Duda
authors.forename: Peter F
authors.initials: PF
authors.lastname: Worcester
authors.forename: Matthew A
authors.initials: MA
authors.lastname: Dzieciuch
authors.forename: James A
authors.initials: JA
authors.lastname: Mercer
authors.forename: Rex K
authors.initials: RK
authors.lastname: Andrew
authors.forename: Bruce M
authors.initials: BM
authors.lastname: Howe
authors.forename: John A
authors.initials: JA
authors.lastname: Colosi
mesh_terms: D000162:Acoustics / Q000295:instrumentation; D004867:Equipment Design; D008962:Models, Theoretical; D009038:Motion; D009791:Oceanography / Q000295:instrumentation / Q000379:methods*; D010140:Pacific Ocean; D012542:Scattering, Radiation; D012623:Seawater; D012815:Signal Processing, Computer-Assisted; D059629:Signal-To-Noise Ratio; D013016:Sound; D013018:Sound Spectrography; D013997:Time Factors; D014159:Transducers