Seismic instruments: article

P. Dergach1
T. Tubanov2
V. Yushin1
A. Duchkov1,3
1 Trofimuk Institute of Petroleum Geology and Geophysics of SB RAS
2 Geological Institute of SB RAS
3 Novosibirsk State Technical University
Journal: Seismic instruments
Tome: 54
Number: 3
Year: 2018
Pages: 22-34
UDK: 550.34.038.3, 550.34.038.8
DOI: 10.21455/si2018.3-2
Keywords: low-frequency deconvolution, frequency characteristics correction, frequency correction of record, natural frequency, reduction of natural frequency, geophone, electrodynamic seismometer, velocimeter, seismic monitoring, local seismology
Аnnotation: The low-frequency deconvolution method allows transforming digital records of electrodynamic seismometers into records of “virtual” sensors of a similar type, but having a lower natural frequency. To carry out the procedure it is necessary to know only the sensor parameters, which can be found in its technical description or obtained by calibration. The implementation of deconvolution in the time domain requires attention when choosing the method of numerical integration, since the use of the simplest methods leads to a distortion of the signal. This is especially noticeable when the sampling rate is close to the geophone's own frequency. A universal approach is presented - the implementation of the algorithm of low-frequency deconvolution in the frequency domain. The testing showed good accuracy both on synthetic tests and on real seismological observations, where the restoration of the low-frequency component of the earthquake record by a seismic geophone was visually demonstrated. The obtained results are primarily relevant for problems in which the low sampling rate of the record is used and high requirements are imposed on the metrological characteristics of the recording equipment (for example, monitoring of local and regional seismicity).