Sabiia Seb
PortuguêsEspañolEnglish
Embrapa
        Busca avançada

Botão Atualizar


Botão Atualizar

Ordenar por: RelevânciaAutorTítuloAnoImprime registros no formato resumido
Registros recuperados: 4
Primeira ... 1 ... Última
Imagem não selecionada

Imprime registro no formato completo
Calibration of acoustic instruments ArchiMer
Demer, Da; Berger, Laurent; Bernasconi, M; Bethke, E; Boswell, K; Chu, D; Domokos, R; Dunford, A; Fassler, S; Gauthier, S; Hufnagle, Lt; Jech, Jm; Le Bouffant, Naig; Lebourges-dhaussy, Anne; Lurton, Xavier; Macaulay, Gj; Perrot, Yannick; Ryan, T; Parker-stetter, S; Stienessen, S; Weber, T; Williamson, N.
Acoustic instrument calibration is fundamental to the quantitative use of its data for estimating aquatic resource abundance. Regular calibrations also allow instrument performance to be monitored to detect changes due to the environment or component dynamics, degradation, or failure. This is the second ICES Cooperative Research Report (CRR) focussed on calibrations of acoustic instruments. The first, CRR No. 144 (Foote et al., 1987), was published during the era of analogue electronics more than a quarter of a century ago. Since then, not only has the acoustic equipment improved vastly with digital electronics and signal processing, but the techniques for applying them to studies of marine organisms have both advanced and diversified. Motivating,...
Tipo: Text
Ano: 2015 URL: https://archimer.ifremer.fr/doc/00586/69821/67711.pdf
Imagem não selecionada

Imprime registro no formato completo
In Situ Quantification of the Suspended Load of Estuarine Aggregates from Multifrequency Acoustic Inversions ArchiMer
Fromant, G.; Floc'H, F.; Lebourges-dhaussy, Anne; Jourdin, F.; Perrot, Yannick; Le Dantec, N.; Delacourt, Christophe.
The study of the suspended particulate matter (SPM) transport is essential to understanding oceans and rivers, for their presence can impact the environment, from marine habitats or water quality degradations to important changes of the seabed morphology. Among a large number of surrogate techniques in traditional water sampling, acoustical methods have the advantage of providing nonintrusive measurements, with high spatial and temporal resolutions. However, the ability of fine-grained sediments to aggregate under the process of flocculation complexifies the interpretation of acoustical measurements. The objective of this paper is to design a simple backscatteringmodel for flocculated sediment suspensions, in order to interpret the information provided by...
Tipo: Text
Ano: 2017 URL: https://archimer.ifremer.fr/doc/00616/72809/72590.pdf
Imagem não selecionada

Imprime registro no formato completo
Including 38 kHz in the standardization protocol for hydroacoustic fish surveys in temperate lakes ArchiMer
Mouget, Anne; Goulon, Chloé; Axenrot, Thomas; Balk, Helge; Lebourges-dhaussy, Anne; Godlewska, Malgorzata; Guillard, Jean.
Hydroacoustics has become a requisite method to assess fish populations and allows to describe the relationships of fish with other elements of the aquatic ecosystem. This nonintrusive method is currently an integral part of the sampling procedures recommended for fish stock assessment by the Water Framework Directive and has been standardized by the European Committee for Standardization [CEN (2014) CSN EN 15910 ‐ Water quality ‐ Guidance on the estimation of fish abundance with mobile hydroacoustic methods, Category: 7577 Water quality. Biological.]. In Europe, hydroacoustic surveys are performed in freshwater using different frequencies. Consequently, there is a need to evaluate if survey results can be compared. This study aimed to carry out in situ...
Tipo: Text Palavras-chave: Fisheries acoustics; Frequencies comparison; Freshwater; Hydroacoustics; Lake; Standardization.
Ano: 2019 URL: https://archimer.ifremer.fr/doc/00484/59605/62619.pdf
Imagem não selecionada

Imprime registro no formato completo
Spatial and temporal variability of zooplankton off New Caledonia (Southwestern Pacific) from acoustics and net measurements ArchiMer
Smeti, Houssem; Pagano, Marc; Menkes, Christophe; Lebourges-dhaussy, Anne; Hunt, Brian P. V.; Allain, Valerie; Rodier, Martine; De Boissieu, Florian; Kestenare, Elodie; Sammari, Cherif.
Spatial and temporal distribution of zooplankton off New Caledonia in the eastern Coral Sea was studied during two multidisciplinary cruises in 2011, during the cool and the hot seasons. Acoustic measurements of zooplankton were made using a shipborne acoustic Doppler current profiler (S-ADCP), a scientific echosounder and a Tracor acoustic profiling system (TAPS). Relative backscatter from ADCP was converted to biomass estimates using zooplankton weights from net-samples collected during the cruises. Zooplankton biomass was estimated using four methods: weighing, digital imaging (ZooScan), ADCP and TAPS. Significant correlations were found between the different biomass estimators and between the backscatters of the ADCP and the echosounder. There was a...
Tipo: Text Palavras-chave: South Pacific; Acoustics; Zooplankton; Vertical migration; Water masses; Mesoscale dynamics.
Ano: 2015 URL: https://archimer.ifremer.fr/doc/00297/40809/39836.pdf
Registros recuperados: 4
Primeira ... 1 ... Última
 

Empresa Brasileira de Pesquisa Agropecuária - Embrapa
Todos os direitos reservados, conforme Lei n° 9.610
Política de Privacidade
Área restrita

Embrapa
Parque Estação Biológica - PqEB s/n°
Brasília, DF - Brasil - CEP 70770-901
Fone: (61) 3448-4433 - Fax: (61) 3448-4890 / 3448-4891 SAC: https://www.embrapa.br/fale-conosco

Valid HTML 4.01 Transitional