Noise directionality estimated using ship tracking data in the Southern Sea of Korea

Abstract

The noise directionality received by an array sensor depends on the spatiotemporal location and distribution of each noise source. Such noise directionality acts as a major factor in influencing the array gain, which determines the ability of the array sensor to detect an underwater target. Thus, the performance of the array sensor can be predicted by estimating the noise directionality. In this study, a modeling method was used to estimate the directionality of ship noise. To verify this method, the results were analyzed by comparing the noise directionality modeled using ship information received from an automatic identification system and the noise directionality measured with a horizontal line array. Although the modeled noise and measured noise directionalities were not perfectly matched, it was confirmed that the peak level and pattern shape of the directional noise pattern are similar. The factors that cause the difference between the two results are (1) the ship source level difference between the actual ship and the model, (2) the impact of ships not using the Automatic Identification System (AIS) as mandatory, and (3) the noise generated by wind, marine organisms, and fluid motion. If these factors are reflected in the noise directionality model using the ship information, better results will be obtained. (C) 2018 The Japan Society of Applied Physics