Seismic instruments: article

Amplitude-frequency calibration of a capacitive electric line in the field
V.A. Davydov
Bulashevich Institute of Geophysics, Ural Branch of the Russian Academy of Sciences
Journal: Seismic instruments
Tome: 59
Number: 1
Year: 2023
Pages: 48–56
UDK: 621.317.3: 550.8.08
DOI: 10.21455/si2023.1-4
Keywords: electrical exploration, capacitive antenna, ungrounded electric line, frequency response, field calibration
Аnnotation: The problem of equivalence of the results of measurements of an alternating electric field using galvanic and capacitive receiving lines, which is relevant for geophysics, is described. The issues of theoretical calculation and calibration methods of capacitive electric antennas are considered. The technology of calibration of ungrounded electric lines by means of comparison with a model (grounded) line directly in the field is proposed and tested. The possibility of obtaining a detailed frequency response of an electric lines using odd harmonics of rectangular signals of an electrical prospecting generator and network harmonics of man-made electromagnetic interference is shown. A field calibration was carried out with the construction of the frequency response of an asymmetric isolated line. There is a good convergence (within the margin of error of field observations) of experimental data with theoretical calculations. It is noted that the points of calibration of an electric antenna using multiple harmonics of industrial electromagnetic fields more accurately correspond to the theoretical amplitude-frequency response, compared with the points of generator calibration. The research results indicate the fundamental possibility of using both grounded and ungrounded lines for various types of electrical exploration, including frequency sensing.