ELECTRICAL PROSPECTING METHOD AND DEVICE TO THIS END (VERSIONS) Russian patent published in 2009 - IPC G01V3/08 

FIELD: physics; measurements.

SUBSTANCE: present invention pertains to geophysical methods of prospecting. An electromagnetic field is generated through generation of a pseudorandom bipolar sequence of packets of periodical current pulses in a transmitter coil. The value of the cross-correlation function is calculated for components (time derivative) of magnetic or electric field and the current form, either with zero-time shift ΔT between time-sequences of the cross-correlation function or without it. From the values of the cross-correlation function with increment, equal to the period of the current pulses, the impulse reaction of the geoelectric medium is determined, which in turn is used to determine the structure of the geoelectric medium. From the difference of impulse reactions on the background and in the absence of primary magnetic field, objects are identified depending on their induced magnetisation. The generator of electromagnetic field has a dc current source, a rectifier bridge, controlled generator of pseudorandom sequences of time intervals, synchronised by a stabilised clock-pulse generator, and a transmitter coil connected to a current sensor. Between the DC current source and the transmitter coil, a current switch is connected, synchronised by a stabilised clock-pulse generator. The generator of pseudorandom sequences of time intervals is connected to the stabilised clock-pulse generator through a frequency divider. In the second version, the transmitter coil generates recurrent packets of current pulses, uniformly distributed according to a random law on the time interval occupied by the packet. In the second version of the device, the current switch is connected to the generator of recurrent packets, randomly and uniformly distributed during pulses, which in turn is connected to the stabilised clock-pulse generator through a frequency divider.

EFFECT: increased accuracy of data from electrical prospecting and reduced labour input.

15 cl, 5 dwg