METHOD AND DEVICE FOR MEASURING IMPEDANCE OF EARTH'S CRUST IN VERY LOW FREQUENCY RANGE OF RADIO-WAVES Russian patent published in 2009 - IPC G01V3/12 

FIELD: physics; geophysics.

SUBSTANCE: invention relates to geological prospecting and can be used for determining effective complex electrical conductivity of the Earth's crust. The method involves measuring surface impedance of the Earth's crust at different frequencies in the very low frequency range of radio-waves from which effective complex electrical conductivity and structure of the geological section are determined. The probing electromagnetic field used is radio-wave emission of a horizontal earthed electrical antenna or system of antennae, powered by highly stable sinusoidal current. The device for realising the method has sensors of horizontal electrical and magnetic components of the electromagnetic field with a preamplifier. The sensor of the horizontal electrical component is made in form of a symmetrical three-electrode earthed electric dipole with a differential preamplifier. The device also has two synchronous detectors, two low-pass filters, a phase regulator and a highly stable reference frequency generator.

EFFECT: more accurate amplitude-phase measurement of surface impedance.

2 cl, 2 dwg