UACE2017 Proceedings: Preliminary Data Analysis of the 3rd Sea Trial for Ambient Noise Imaging with Acoustic Lens

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  • Session:
    Towards Automatic Target Recognition. Detection, Classification and Modelling
  • Paper:
    Preliminary Data Analysis of the 3rd Sea Trial for Ambient Noise Imaging with Acoustic Lens
  • Author(s):
    Kazuyoshi Mori, Hiroyuki Kawahara, Hanako Ogasawara, Takenobu Tsuchiya
  • Abstract:
    We previously designed and produced a prototype system with an aspherical lens that had a 1-m aperture diameter and a 2-D receiver array with 127 elements for ambient noise imaging (ANI). We verified that this system could realize the directional resolution, which is the beam width of 1 degree at the centre frequency of 120 kHz, a horizontal field of view of 15 degrees, and vertical of 9 degrees. In November 2014, a 2nd sea trial was conducted to evaluate the performance of this ANI system. The detected images mapping intensities of target scatterings successfully expressed the shapes of some silent targets, consisting of panels and spheres under natural ocean ambient noise, generated mainly by snapping shrimps. In the present study, we attempted to detect images of silent targets with frequency-dependent echoes generated by snapping shrimp noises. The 3rd sea trial was conducted to detect two sphere targets in November 2016 in Uchiura Bay. Each target was designed to have a frequency response peak of 80 or 160 kHz. Our ANI system successfully received the different frequency-dependent echoes from the two targets. In the near future, we plan to create target images from received echoes to express target frequency dependence with RGB additive colour mixing. Here, the received frequency band from 50 to 200 kHz will be divided into three parts, and the received intensities of low-, mid-, and high-frequency bands will be assigned to Red, Green, and Blue colour, respectively.
  •   Download the full paper

Contact details

  • Contact person:
    Prof Kazuyoshi Mori
  • e-mail:
  • Affiliation:
    National Defense Academy of Japan
  • Country:
    Japan

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