Patent ID: 8120355
Filing Date: 2012-02-21
Classification: G01R

Abstract:
1. A magnetic anomaly detector, comprising: a magnetic field detector for generating analog signals in response to an incident magnetic field; a sample-and-hold device coupled to said magnetic field detector for generating time-quantized analog signals from said analog signals; a discrete-time differentiator coupled to said sample-and-hold device, for differentiating said time-quantized analog signals to thereby generate differentiated signals; a low-pass filter coupled to said differentiator, for rejecting spectral frequencies above a given value and for passing spectral frequencies below said given value, to thereby generate filtered signals; a Fourier transform device coupled to said low-pass filter for receiving said filtered signals, and for transforming said filtered signals into a frequency-amplitude spectrum; a reference spectrum source for generating at least one frequency spectrum representing the presence of a magnetic anomaly; an error detector coupled to said Fourier transform device and to said reference spectrum source, for generating an error signal representative of differences between said reference spectrum and the frequency-amplitude spectrum; and an alarm coupled to said error detector for responding to identification of one of a match and no match between said reference spectrum and the frequency-amplitude spectrum.