Analysis and Classification of Broadband Acoustic Echoes from Individual Live Fish using the Pulse Compression Technique

摘要

This study identified the species-specific, frequency-dependent characteristics of broadband acoustic scattering that facilitate classifying fish species using the pulse compression (PC) technique. Controlled acoustic scattering laboratory experimentswere conducted with nine commercially important fish species using linear chirp signals (95-220 kHz) over an orientation angle range of ±45° in the dorsal plane at approximately 1 ° increments. The results suggest that the angular-dependent characteristics of the broadband echoes and the frequency-dependent variability in target strength (TS) were useful for inferring the fish species of interest. The scattering patterns in the compressed pulse output were extremely complex due to morphological differences among fish species, but the x-ray images strongly suggested that spatial separation correlated well with scattering for the head, skeleton, bone, otoliths, and swim bladder within each specimen.