The study of frequency characteristics of target strength of fish by using frequency modulation signal

在本研究中，我们尝试利用调频信号来测量鱼体的目标强度。我们不仅关注FISH反射波的强度，而且还关注宽带频率响应。这可能会导致先进的声学测量。首先，我们测量了水箱中4条鱼目标强度的宽带频率特性。通过照片和软X射线对鱼体和鱼囊的形态进行测量。利用Kirchhoff-ray模式模型计算了FISH的理论频率响应模式。我们证实了测量模式与理论趋势是一致的。此外，我还开发了一种通过光学(立体相机)确认海洋实验中鱼类物种的确认技术。

In this study, we tried to measure the target strength of fish by using the frequency modulation signal. And we focus on not only intensity of reflected wave from fish, but also broadband frequency responses. It may be lead to advanced acoustic survey. First, we measured broadband frequency characteristics of target strength of 4 fish in a water tank. The shape of body and swim bladder of fish were measured by photos and soft X-ray. The theoretical frequency responses pattern of fish were calculated by using the Kirchhoff-ray mode model. we confirmed that the measurement pattern and theoretical were same trend. Furthermore, I developed confirmation technique by the optics(stereo camera) for fish species confirmation at a sea experiment.