METHOD OF SUPPRESSING DIRECT FIELD SIGNAL IN ELECTROMAGNETIC INDUCTION PROBING AND DEVICE FOR ITS IMPLEMENTATION Russian patent published in 2024 - IPC G01V3/10 

FIELD: measurement; electricity.

SUBSTANCE: invention relates to electromagnetic induction probing, in particular to suppression of a direct field signal in a receiving signal. Direct field signal suppression is performed in a filtering unit using a multichannel adaptive RLS algorithm by determining the weight coefficients with minimizing the discrepancy of the objective function, which characterizes the difference between the measured and simulated signals from the receiving coil, using the obtained simplex coefficients in accordance with the Nelder-Mead method to find the unconstrained minimum of the objective function. Percentage estimation of the presence of a direct field signal in the recorded data is carried out and the amplitude and phase of the useful signal are calculated based on the weight coefficients. Device consists of a generator coil, a harmonic signal generator, a current sensor installed inside the generator coil and providing information on the forward field, as well as one or a set of receiving coils. Signals from the coils are connected through the corresponding circuits, having a band-pass filter and an analogue-to-digital converter, to the filtration unit, where the amplitude and phase of the useful signal are calculated using a multichannel adaptive RLS algorithm.

EFFECT: high reliability of extracting a useful signal and simplifying the design of geophysical equipment for electromagnetic sounding.

2 cl, 3 dwg, 2 tbl