Identification of a wharf wall condition using an Oblique Side Scan Sonar approach

Port of Tanjung Perak has several terminals, one of which is Nilam Terminal. Nilam Terminal itself is a Multipurpose Terminal and one of the terminals with the highest loading and unloading activities at Port of Tanjung Perak. With the high level of activities occurring at the Nilam Terminal, monitoring and maintenance of the wharf wall conditions are needed, so that the ongoing activities can run smoothly. Therefore, the purpose of this study is to identify the condition of the wharf walls with acoustic imaging using the Oblique Side Scan Sonar approach and provide an overview of the condition of the Nilam Terminal. To produce a picture of the wharf wall with an acoustic image requires Side Scan Sonar data, where during installation, the tool is turned 90 so that it faces the wharf wall. In this study, three types of corrections were made, which are Altitude Correction, Slant Range Correction, and Time-Varying Gain. In order to validate the Side Scan Sonar results, use digital cameras to increase the credibility of interpretation results. The length of the wharf wall surveyed is 268.62 meters with a total area of 3223.44 m2. In that area there are three locations that are interpreted as holes in the wharf wall. The position of the first hole at the UTM (Universal Transverse Mercator) coordinates 49S A Zone is at (690268.97 m; 9203336.09 m) with an area of 2.07 m2, the position of the second hole is at (690224.71 m; 9203404.98 m ) with an area of 1.91 m2, and for the position of the third hole is (690208.15 m; 9203438.66 m) with an area of 1.21 m2.