Detection of magnetic anomaly signal by applying adjustable weight functions

The author describes a method of detecting a magnetic field signal due to a magnetized object on a magnetometric record where the signal is weak. In the method, the record is divided into intervals and the measurements in each are approximated by a set of dipole field curves where the weighted residuals are minimized through the iterative technique. To convert the originally indeterminate problem into a determinate one, the weight function proportional to some positive power of the distance between the assumed location of the dipole and the point for measurement is introduced. By adjusting the exponent of the function, the estimated location of the dipole tends to converge to the middle of the interval when no signal exists, whereas it converges to the true location when the signal is included. As an example, the field signal of a small can of tin plate could be detected at a distance fifteen times its length, where the signal-to-noise ratio was nearly unity.<
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