Second-order perturbations of peak-arrival times due to sound-speed variations

Skarsoulis, EK; Athanassoulis, GA

dc.contributor.author	Skarsoulis, EK	en
dc.contributor.author	Athanassoulis, GA	en
dc.date.accessioned	2014-03-01T01:14:09Z
dc.date.available	2014-03-01T01:14:09Z
dc.date.issued	1998	en
dc.identifier.issn	0001-4966	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/12884
dc.subject.classification	Acoustics	en
dc.subject.other	acoustics	en
dc.subject.other	broadband data	en
dc.subject.other	perturbation	en
dc.subject.other	tomography	en
dc.subject.other	acoustics	en
dc.subject.other	article	en
dc.subject.other	pressure	en
dc.subject.other	priority journal	en
dc.subject.other	sea	en
dc.subject.other	sound	en
dc.subject.other	theory	en
dc.subject.other	tomography	en
dc.subject.other	velocity	en
dc.title	Second-order perturbations of peak-arrival times due to sound-speed variations	en
heal.type	journalArticle	en
heal.identifier.primary	10.1121/1.423971	en
heal.identifier.secondary	http://dx.doi.org/10.1121/1.423971	en
heal.language	English	en
heal.publicationDate	1998	en
heal.abstract	The concept of peak arrivals is used to study the second-order arrival-time behavior of broadband tomographic signals due to sound-speed variations. Peak arrivals, defined as the local maxima of the pressure amplitude at the receiver in the time domain, are the exact theoretical counterparts of the experimental observables in ocean acoustic tomography, and they offer a uniform description of all the peaks in the arrival pattern, independent of whether they can be resolved as ray/modal arrivals or not. Closed-form expressions for the first and second sound-speed derivatives of peak-arrival times are derived in terms of sound-speed derivatives of the Green's function. Using normal-mode theory the sound-speed derivatives of the Green's function are analytically expressed for: the case of a range-independent medium in terms of eigenvalues and eigenfunctions at the reference state. Numerical examples are given for range-independent environments motivated from the Thetis-2 experiment, showing different kinds of nonlinear behavior of the arrival times in the large and the fine scale and demonstrating the performance of the second-order approach. (C) 1998 Acoustical Society of America. [S0001-4966(98)05012-7].	en
heal.publisher	AMER INST PHYSICS	en
heal.journalName	Journal of the Acoustical Society of America	en
dc.identifier.doi	10.1121/1.423971	en
dc.identifier.isi	ISI:000077367500023	en
dc.identifier.volume	104	en
dc.identifier.issue	6	en
dc.identifier.spage	3313	en
dc.identifier.epage	3325	en