• Journal of the Korean Society of Marine Environment & Safety
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• v.24 no.4
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• pp.459-466
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• 2018

Hazardous and Noxious Substances (HNS) are defined as substances that are likely to create a significant impact on human health and marine ecosystem when they are released into the marine environment. Recently, as the volume of HNS transported by ships increases, the rate of leakage accidents also increases. Therefore, research should be conducted to control and monitor sunken materials from the viewpoint of technology development for hazardous material leakage accident response. In this paper, acoustic detection experiments were carried out using HNS substitute materials in order to confirm the possibility of acoustic detection of sunken HNS on the sediment. The castor oil, which has a similar acoustic impedance with chloroform, is used as a substitute. 200 kHz high frequency signals were used to discriminate the reflected signals and measure reflection loss from the interface between water and castor oil. The reflection loss measured is in good agreement with the modeling results, showing a possibility of acoustic detection for sunken HNS.

• Journal of the Korean Society of Marine Environment & Safety
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• v.28 no.spc
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• pp.18-22
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• 2022

Because it is difficult to apply direct and optical detection techniques to sunken hazardous and noxious substances (HNS), effective acoustic detection techniques are required to detect sunken HNS in water. In this study, the possibility of acoustic detection of sunken HNS was investigated through backscattering signal measurement experiments using chloroform, a sunken HNS. After establishing a pool in an acrylic tank, backscattering signals were measured according to the presences or absence of chloroform by varying the grazing angle from 90° to 50° in 0.5° intervals using a pan&tilt system. A directional transducer transmitted and received sinusoidal signals with a frequency of 200 kHz and a pulse length of 25 ㎲ in a monostatic state. When chloroform was deposited, the received level of the backscattering signal at the interface between water and chloroform became low at a grazing angle of approximately 80° or smaller. Based on the backscattering signal results obtained at the interface between water and chloroform, the possibility of acoustic detection of sunken HNS was demonstrated.

• Proceedings of KOSOMES biannual meeting
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• 2017.11a
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• pp.158-158
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• 2017