1990 Volume 56 Issue 8 Pages 1225-1229
In the former report, informations of ultrasonic echo shape, namely amplitude and form of envelope of the signal received by two balls were analyzed. And the possibility of making use of the information effectively was suggested. In the present paper, the relationship between the information about the pulse shape by the two balls and that by the individual fish was discussed. The measurement system and the analysis method of signal were almost the same as in the previous paper. From the measured results, in regard to ultrasonic reflection characteristic of the red sea bream, it was presumed that the characteristic was to be influenced more by the internal structure than by the external form. Accordingly, it was noted that the red sea bream had two imaginary acoustic centers in the internal structure. And from the simulated results, the distance between the two centers was assumed to be countable.