Magnetic Anomaly Characteristics Analysis of a Finite-Length Submarine Cable

Submarine cables are a typical weak magnetic target. Studying the magnetic anomaly principle of these cables and establishing their magnetic anomaly model are the bases of realizing magnetic detection, location, and recognition. The magnetic anomaly model of a 2D, infinite-length, horizontal cylinder is traditional and typical. However, when the cable is laid on a polygonal line under the constraints of geographical conditions or it is broken, the traditional model is no longer applicable. In this study, a magnetic anomaly analysis model of a finite-length submarine cable was proposed based on magnetic anomaly theory of finite-length horizontal cylindrical shells. The characteristics, applicability, and magnetic anomaly variation law of the model were analyzed. Exploration of the critical length ratios for the magnetic anomaly of a finite-length submarine cable that cannot be calculated by the traditional model improves the present magnetic anomaly theory of submarine cables.