Detection method and detector of a disruption, positioning method and system using said method

摘要

This method for detecting a disturber of magnetic field amplitude comprises:
the emitting (62) of several magnetic fields of different frequencies from a same uniaxial magnetic field source, the amplitudes of the magnetic field emitted at two different unspecified frequencies being related to each other by a predetermined ratio,the measurement (64) of the amplitude of these magnetic fields at different frequencies by means of a same sensor, andthe reporting (70) of an amplitude disturber if a ratio between two of said measured amplitudes diverges from a predetermined threshold of the predetermined ratio which relates the amplitudes of the magnetic fields emitted at the same frequencies and, if not, the absence of any reporting.

主权项

1. A method for detecting a disturber of an amplitude of a magnetic field amplitude, the disturber being in proximity to a uniaxial magnetic field source, said method comprising:
emitting several magnetic fields from the uniaxial magnetic field source, said several magnetic fields being emitted at at least three different frequencies, f1, f2, . . . fj, wherein, of said several magnetic fields emitted, two magnetic fields having different unspecified frequencies chosen among said at least three different frequencies f1, f2, . . . fj, have amplitudes when emitted being related to each other by a predetermined ratio, which ratio is constant and equal to one, using a sensor spaced from said uniaxial magnetic field source, measuring amplitudes of said two magnetic fields emitted at said different unspecified frequencies, and reporting an amplitude disturber when a ratio between the measured amplitudes of said two magnetic fields emitted diverges from one by a predetermined threshold.