Multifrequency acoustic scattering characteristics of jack mackerel by KRM model

This study was focused on acoustic scattering characteristics of jack mackerel (Trachurus japonicus) at frequency 38, 70, and 120 kHz by Kirchhoff-ray mode (KRM) model. The body length (BL) of 16 individuals ranged in 12.2~22.0 cm ($mean{\pm}S.D.$: $17.8{\pm}3.2cm$) and the swimbladder length ranged in 4.2~8.6 cm ($mean{\pm}S.D.$: $6.6{\pm}1.6cm$) and the swimbladder cross section ranged in $1.7{\sim}6.6cm^2$ ($mean{\pm}S.D.$: $3.8{\pm}1.6cm^2$). This result shows that results correlate well between the BL and the length and cross section of swimbladder. The swimbladder angle ranged in $7{\sim}12^{\circ}$ and the maximum TS values ranged in $-16{\sim}-5^{\circ}$ at tilt angle. The averaged TS-to-BL relationship were $TS_{38kHz}=20{\log}_{10}BL-65.33$ ($R^2=0.66$), $TS_{70kHz}=20{\log}_{10}BL-65.90$ ($R^2=0.67$), and $TS_{120kHz}=20{\log}_{10}BL-66.65$ ($R^2=0.65$). These results can be used fundamental data in order to estimate distribution and biomass of jack mackerel by using hydro-acoustic method.

KRM 모델을 이용한 전갱이의 다주파수 음향산란특성