System and method of detecting the proximity of an alternating magnetic field

摘要: A system for, and a method of, detecting the proximity of source an alternating magnetic field, such as that emanating from power transmission cables, comprising sensor coil sensitive to field under detection, processing means derive signal induced in warning indicative cancelling operable cancel earth's region coil. The may be one pair provide representative directional heading with respect system, which embodiment is particularly useful helicopters for cables.