海洋音響学会誌
Online ISSN : 1881-6819
Print ISSN : 0916-5835
ISSN-L : 0916-5835
44 巻 , 1 号
選択された号の論文の2件中1~2を表示しています
論文
  • Kohei HASEGAWA, Keiichi UCHIDA, Yoshinori MIYAMOTO
    2017 年 44 巻 1 号 p. 1-12
    発行日: 2017/01/01
    公開日: 2018/04/28
    ジャーナル フリー

    Most ultrasonic transmitters (pingers) used for behavioral surveys of aquatic animals send a variety of information by changing the interval of the pulses. The reflection of a pulse generally occurs at the sea surface and/or the bottom. Reflection is a critical problem in considering the measurement error generated by the arrival-time delay of the reflected pulse. We conducted a field experiment to evaluate the effect of reflection, and discussed ways to prevent the effect. In this paper, we used a tracking-type ultrasonic telemetry system. The pinger of the system measures its depth by changing the interval of two pulses. In order to evaluate the paths of the reflected pulses, we measured the difference in arrival time between a direct pulse that propagated the direct path to the hydrophone and reflected pulses. We observed the variation in arrival-time difference in field experiments. Results showed that reflected surface pulses easily affected the system. Improvements to the ultrasonic telemetry system helped to prevent the effect of reflection, and we demonstrated the effectiveness of the improved system in an additional field experiment. The improved system could measure the depth data without the effects of reflection. We also discuss a more optimal configuration for preventing the measurement error from the additional experimental data.

研究速報
feedback
Top