Investigation of Ship Navigation in Harbor Waterways Via Magnetic Guidance.

摘要

A ship guidance system using the magnetic field of one or more cables laid on the bottom of a waterway is investigated. Emphasis is placed on those aspects that are related to a specific system used by the U.S. Coast Guard during a field test in Muskegon Channel,with the sensors mounted on the U.S. Coast Guard cutter Woodbine. The essential feature of the sensing system used is the vanishing of the vertical component of the magnetic field directly above the cable. Aspects investigated include the dependence of the magnetic field on channel depth,water conductivity,frequency,and sensor height above the water;various ways of providing a return path for the current,such as through the water and ground or through additional cables;and the effects of masses of ferromagnetic materials with emphasis on the sensor-carrying vessel,passing ships,and piers along the channel edge. It is assumed that the sensor-carrying vessel is a Great Lakes bulk carrier. (Modified author abstract)