METHOD AND DEVICE FOR DIRECT SEARCHING OF GEOLOGICAL OBJECTS Russian patent published in 1995 - IPC

FIELD: geophysical inspection. SUBSTANCE: electromagnet field is excited in tested medium by means of axially symmetric introduction of electric current into Earth by means of drive-pulse generator 1. The first output of the generator is connected with power electrodes 2 disposed at central part of the circle which is formed by other power electrodes 3 connected with the second output of the generator by corresponding ray sections 4 of power network; the sections are disposed along the radiuses of the circle in equal angles which do not excess over 60 deg. Currents fed to electrodes 3 are changed by means of current controls 5 which are controlled by unit 6 and brought into ray sections 4. Currents are changed either according to the law brought into unit 8 of central processor, or till achieving values at which speed of signal decay of availability of electric current is maximal or/and signal of availability of magnetic field is minimal. Value of current in generator 1 and in ray sections 4 is controlled by current measuring unit 10. The signal is assigned by numerical values by means of meters 13 which are connected in series, and signal of availability of electric field - by means of meters 13 connected in parallel. Results of measurements are transmitted simultaneously to registrar 11 through control unit 12 and common bus 7. Then the signals are sent to processing unit 17 through interface module 16. Multidimensional electromagnetic image of tested medium is generated in processing unit 17. Results of identification of the image are used for building geological section. More optimal spatial-temporal structure of excited electromagnetic field is provided, as a result, the higher resolution is available to reveal thin weak-conducting geological objects of "bed" type. EFFECT: improved precision; improved reliability. 2 cl, 3 cl, 8 dwg