Surface-induced errors in target strength and position estimates during horizontal acoustic surveys

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F60077344%3A_____%2F17%3A00479371" target="_blank" >RIV/60077344:_____/17:00479371 - isvavai.cz</a>

Nalezeny alternativní kódy

RIV/60076658:12310/17:43895576

Výsledek na webu

<a href="http://dx.doi.org/10.1016/j.fishres.2016.12.017" target="_blank" >http://dx.doi.org/10.1016/j.fishres.2016.12.017</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1016/j.fishres.2016.12.017" target="_blank" >10.1016/j.fishres.2016.12.017</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Surface-induced errors in target strength and position estimates during horizontal acoustic surveys

Popis výsledku v původním jazyce

Horizontally-aligned, fixed and mobile, transducers are routinely deployed at depths of 0.5-0.75 m to survey the surface layer of waterbodies for fish. However, simulations and measurements demonstrate that a smooth surface can cause serious errors in the target strength (TS) and split-beam angular position estimates. Errors in TS up to 10 dB and depth position up to 0.5 m were observed. Simulations suggested that multi-path signal propagation interfered with the direct path of that signal. Furthermore, when a standard target (calibration copper sphere) was moved away from the transducer at fixed depths, the estimated TS and depth of the target started to oscillate as a function of range. The amplitude increased with increasing range. The frequency decreased from the oscillation start until a certain range where the oscillation stopped. The region of oscillation depended on both the transducer and target depth. Horizontal observations of known fish echoes behaved similarly. Experiments in a lake showed that the influence from the surface disappeared when the surface became rippled due to wind.

Název v anglickém jazyce

Surface-induced errors in target strength and position estimates during horizontal acoustic surveys

Popis výsledku anglicky

Horizontally-aligned, fixed and mobile, transducers are routinely deployed at depths of 0.5-0.75 m to survey the surface layer of waterbodies for fish. However, simulations and measurements demonstrate that a smooth surface can cause serious errors in the target strength (TS) and split-beam angular position estimates. Errors in TS up to 10 dB and depth position up to 0.5 m were observed. Simulations suggested that multi-path signal propagation interfered with the direct path of that signal. Furthermore, when a standard target (calibration copper sphere) was moved away from the transducer at fixed depths, the estimated TS and depth of the target started to oscillate as a function of range. The amplitude increased with increasing range. The frequency decreased from the oscillation start until a certain range where the oscillation stopped. The region of oscillation depended on both the transducer and target depth. Horizontal observations of known fish echoes behaved similarly. Experiments in a lake showed that the influence from the surface disappeared when the surface became rippled due to wind.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

40103 - Fishery

Projekt

Výsledek vznikl pri realizaci vícero projektů. Více informací v záložce Projekty.

Návaznosti

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Rok uplatnění

2017

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Fisheries Research

ISSN

0165-7836

e-ISSN

—

Svazek periodika

188

Číslo periodika v rámci svazku

APR

Stát vydavatele periodika

NL - Nizozemsko

Počet stran výsledku

8

Strana od-do

149-156

Kód UT WoS článku

000394077100015

EID výsledku v databázi Scopus

2-s2.0-85008199306