GEOPHYSICAL SURVEY METHOD AND DEVICE FOR RECORDING PARAMETRES OF EARTH'S NATURAL PULSED ELECTROMAGNETIC FIELD Russian patent published in 2011 - IPC G01V3/08 

FIELD: physics.

SUBSTANCE: antennae of n devices for detecting natural pulsed electromagnetic field of the Earth (NPEMFE), where n=2, 3, 4,…, are placed on surveyed territory at a distance of not more than 1 m from each other. Antennae are oriented in the same given directions for identical reception channels. Synchronous measurement of NPEMFE is carried out in upon arrival of said pulses and the number of said pulses is determined, wherein measurement is carried out in the very low frequency range in not less than two different directions. The minute-average value of intensity is determined and sensitivity of the channels is adjusted based on the obtained values on a typical daily variation of NPEMFE. Sensitivity of channels receiving signals from the same directions is levelled. The obtained device adjustment parametres are stored. Synchronous measurements of time variations of the field are then taken by all devices during working hours. The average value of intensity for each device and each signal reception direction is determined. The devices are classified into reference and route devices. The reference devices are those whose readings are closer to the average values of readings of all devices. A base device is selected from the reference devices, where the said base device records the signal intensity value which is closest to the average values of readings of the reference devices. Adjustments for non-identity are determined for all devices and each reception direction. Reference devices, including the base device, are installed in selected points of the surveyed territory. Antennae of their identical reception channels are oriented in the same given directions. Measurements in continuous mode are carried out using parametres determined during set up from an accurate time signal. Profiling is carried out using the route devices. Adjustments on non-identity are made to readings of all devices. Variations of measured parametres of the NPEMFE are determined along the profile by removing time variations, recorded by reference devices, from readings of route devices. Presence of geophysical anomalies on the analysed profile is determined. Borders of the anomaly are mapped and the obtained results undergo geological interpretation.

EFFECT: reduced errors.

9 dwg, 2 tbl