Cristin-resultat-ID: 1941528
Sist endret: 30. september 2021, 14:59
Resultat
Vitenskapelig foredrag
2021

Nonlinear higher harmonics and crosstalk in broadband multi-channels echosounders

Bidragsytere:
  • Babak Khodabandeloo
  • Egil Ona
  • Gavin Macaulay og
  • Rolf Korneliussen

Presentasjon

Navn på arrangementet: ICES WGFAST and ICES-FAO WGFTFB
Sted: Bergen
Dato fra: 19. april 2021
Dato til: 23. april 2121

Arrangør:

Arrangørnavn: ICES

Om resultatet

Vitenskapelig foredrag
Publiseringsår: 2021

Beskrivelse Beskrivelse

Tittel

Nonlinear higher harmonics and crosstalk in broadband multi-channels echosounders

Sammendrag

One of the prominent features of nonlinear acoustic propagation is the dependence of propaga-tion speed on the acoustic pressure amplitude. A consequence is the distortion of the transmitted acoustic signal as it propagates through the medium, and hence energy leakage from the prima-ry frequency band to harmonic frequencies. When operating several broadband echosounder channels with non-overlapping frequency bands, the generated higher harmonics from one channel may overlap and interfere with the primary frequency band of others. This interference is called crosstalk and can appear as spurious targets above and/or below the main target in pulse compressed echograms and. in addition, affect the measured backscattering frequency response of targets. Here, the nonlinear propagation of frequency-modulated acoustic waves in a directional beam are modelled and suggestions are made to reduce the crosstalk for simultane-ous operation. Efficiency of the suggested method is demonstrated by measurements on the strong echo from a flat seafloor. In addition, synchronized operation of broadband echosounder channels with reduced crosstalk is confirmed by comparing the measured and theoretically es-timated target strength of a calibration sphere.

Bidragsytere

Babak Khodabandeloo

  • Tilknyttet:
    Forfatter
    ved Økosystemakustikk ved Havforskningsinstituttet

Egil Ona

  • Tilknyttet:
    Forfatter
    ved Institutt for biovitenskap ved Universitetet i Bergen

Gavin John Macaulay

Bidragsyterens navn vises på dette resultatet som Gavin Macaulay
  • Tilknyttet:
    Forfatter
    ved Økosystemakustikk ved Havforskningsinstituttet

Rolf Korneliussen

  • Tilknyttet:
    Forfatter
    ved Økosystemakustikk ved Havforskningsinstituttet
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