Range estimation of bowhead whale (Balaena mysticetus) calls in the Arctic using a single hydrophone

TitleRange estimation of bowhead whale (Balaena mysticetus) calls in the Arctic using a single hydrophone
Publication TypeJournal Article
Year of Publication2014
AuthorsBonnel J., Thode A.M, Blackwell S.B, Kim K., Macrander A.M
JournalJournal of the Acoustical Society of America
Volume136
Pagination145-155
Date Published2014/07
Type of ArticleArticle
ISBN Number0001-4966
Accession NumberWOS:000339163800024
Keywordsdistance; frequency; geoacoustic inversion; location; migration; sea; shallow-water; source localization; sperm-whales; tracking
Abstract

Bowhead whales generate low-frequency calls in shallow-water Arctic environments, whose dispersive propagation characteristics are well modeled by normal mode theory. As each mode propagates with a different group speed, a call's range can be inferred by the relative time-frequency dispersion of the modal arrivals. Traditionally, at close ranges modal arrivals are separated using synchronized hydrophone arrays. Here a nonlinear signal processing method called "warping" is used to filter the modes on just a single hydrophone. The filtering works even at relatively short source ranges, where distinct modal arrivals are not separable in a conventional spectrogram. However, this warping technique is limited to signals with monotonically increasing or decreasing frequency modulations, a relatively common situation for bowhead calls. Once modal arrivals have been separated, the source range can be estimated using conventional modal dispersion techniques, with the original source signal structure being recovered as a by-product. Twelve bowhead whale vocalizations recorded near Kaktovik (Alaska) in 2010, with signal-to-noise ratios between 6 and 23 dB, are analyzed, and the resulting single-receiver range estimates are consistent with those obtained independently via triangulation from widely-distributed vector sensor arrays. Geoacoustic inversions for each call are necessary in order to obtain the correct ranges. (C) 2014 Acoustical Society of America.

DOI10.1121/1.4883358
Integrated Research Themes: 
Student Publication: 
No
sharknado