A geophone-based and low-cost data acquisition and analysis system designed for microtremor measurements


Kafadar Ö.

GEOSCIENTIFIC INSTRUMENTATION METHODS AND DATA SYSTEMS, cilt.9, ss.365-373, 2020 (SCI Expanded İndekslerine Giren Dergi)

  • Cilt numarası: 9 Konu: 2
  • Basım Tarihi: 2020
  • Doi Numarası: 10.5194/gi-9-365-2020
  • Dergi Adı: GEOSCIENTIFIC INSTRUMENTATION METHODS AND DATA SYSTEMS
  • Sayfa Sayıları: ss.365-373

Özet

The commercial data acquisition instruments designed for three-component microtremor measurements are usually  very  expensive  devices.  In  this  paper,  a  low-cost,computer-aided,  and  geophone-based  system  designed  to record, monitor, and analyze three-component microtremor data is presented. This proposed system is not a simple data acquisition  system.  It  is  also  an  integrated  system  developed to interpret the microtremor data using the horizontal-to-vertical spectral ratio (H/V) method without any external software. Therefore, the H/V peak frequency and amplitude can be easily estimated using this system. The proposed  system  has  several  features  such  as  a  200 Hz  sampling  frequency,  approximately  72 dB  dynamic  range,  text data format, and data analysis tools. This system consists of a graphical user interface developed by using the .NET Framework 4.5.2 and external hardware that includes signal conditioning circuits, voltage converter circuit, external analog-to-digital converter, and Arduino Uno board. The proposed system uses low-cost vertical and horizontal geophones with a 4.5 Hz natural frequency to measure three-component microtremor  data.  The  developed  software  undertakes  many tasks  such  as  communication  between  the  external  hardware and computer, transferring, monitoring, and recording the  seismic  data  to  the  computer,  and  interpretation  of  the recorded data using the Nakamura method. Channel consistency and internal noise measurement tests were performed to demonstrate the accuracy and precision of the proposed system. The proposed system was compared to a commercial triaxial digital seismograph, and satisfactory results were obtained. The developed system is a completely open-source and  open-hardware  system  and  can  be  easily  used  in  academic studies conducted by researchers and university students who are interested in seismic ambient noise analysis.