Coly Y., Perrot Yannick, Brehmer Patrice, Machu Eric, Sow B.A. (2022). Estimation and correction of depth range and echo level errors due to water-column temperature and salinity on sound scattering layer [résumé]. In :
Jech M. (ed.). Working group of fisheries acoustics, science and technology (WGFAST). ICES Scientifics Reports, 4 (54), 47-48. ICES. Working Group of Fisheries Acoustics, Science and Technology (WGFAST), Somone (SEN ), 2022/04/25-28. ISSN 2618-1371.
Titre du document
Estimation and correction of depth range and echo level errors due to water-column temperature and salinity on sound scattering layer [résumé]
ICES. Working Group of Fisheries Acoustics, Science and Technology (WGFAST), Somone (SEN ), 2022/04/25-28
Water temperature and salinity are the key environmental parameters involved in the acoustic signal processing. In absence of clear procedure, temperature and salinity value are usually used at a fixed point in the water column to estimate the sound celerity in the studied area. Consider-ing temperature and salinity as having negligible effects in estimates of acoustic variables may lead to errors in dependent acoustic variables as the volume backscattering coefficient Sv, the nautical area backscattering coefficient sA and the target distance, i.e., depth for vertical echo-sounder. We examine the impact of environmental errors and their effects on the level of Sv, sA and range r. The results shown that the effect may not be negligible. The nautical area backscat-tering coefficient sA was the most affected by environmental errors. The deep ocean areas were the most concerned by these errors vs. surface and shallow coastal areas. Failure to correct for environmental errors in acoustic studies can lead to inaccurate results on the positions of the targets studied and biomass assessment. Abacuses were built to identify areas of interest where environmental corrections should be implemented and we share corrective code integrating tem-perature and salinity water profile for fisheries acoustics data correction.
Plan de classement
Sciences du milieu [021]
;
Limnologie physique / Océanographie physique [032]
