侧扫声纳在海底光缆维护工程中的应用

海底光缆系统是现代通信的主要载体之一。光缆铺设于海底后，在自然和人为的作用下，其在海底状态可能随时间会发生变化，甚至遭到损害，需对其进行维护。维护工程中首先需要对光缆在海底的实际状况和所在区域的海底面特征有一个比较清楚的了解。侧扫声纳为此提供了一种十分经济有效的手段，它通过探测出露于海底的光缆或埋设于海底光缆的埋设沟痕等，确定光缆在海底位置、检测其在海底状况、调查其所在海区的海底面特征，并可用于检查光缆维护施工的工作效果等。本文结合APCN2海底光缆系统特殊区段护缆安装工程这一实际例子，讨论了侧扫声纳海底扫测资料在海底光缆系统维护工程中的应用，表明侧扫声纳在海底光缆维护工程中有广泛应用前景。但是，侧扫声纳无法有效探测既不出露海底又没有明显埋设沟痕的海底光缆，同时也无法确定光缆的埋设深度，对这些状况的了解须结合使用其它专门探测设备。

SIDE SCAN SONAR APPLICATIONS IN UNDERSEA FIBER-OPTIC CABLE MAINTENANCE PROJECTS

Undersea fiber-optic cable system is one of important carriers of modern telecommunications. After cable installations, its burial situations on and/or in seabed may change as time goes on and even cable damages and faults can happen, so engineering maintenance is often required. One of basic jobs during cable engineering maintenance is to know cable's real burial conditions on and/or in seabed and surrounding seabed features. Side scan sonar is one of most economic and effective methods for this. It can locate cables on seabed based upon directly tracked cables on sonar record and/or possible cable burial trench, and reveal cable burial conditions and seabed features, and be used to evaluate maintenance effectiveness. Taking APCN2 fiber-optic cable system Guard Wire Protection Project on the East China Sea Continental shelf as an example, this paper discussed side scan sonar data applications for undersea cable maintenance. It showed that side scan sonar is a very useful tool and has a wide application prospect. However, side scan sonar is unable to track the cables wholly buried beneath the seafloor and without obvious burial trench on seabed, and it also can not be used to measure the cable burial depths. In these cases, other more complicated cable tracking techniques based on magnetic and electromagnetic principles should be deployed.