A Multi-Channel Borehole Strain Measurement and Acquisition System Based on FPGA.

Area of Science:

• Geophysics
• Earth Science
• Instrumentation

Background:

• Traditional borehole strain measurement systems often rely on analog circuits, which can be limited in processing power and flexibility.
• Improving signal-to-noise ratios and dynamic range is crucial for accurate geophysical observations.

Purpose of the Study:

• To design and validate a Field Programmable Gate Array (FPGA)-based borehole strain measurement system.
• To leverage digital signal processing for enhanced data quality and system adaptability.

Main Methods:

• Extensive use of digital signal processing operations on an FPGA to replace analog circuits.
• Data filtering and denoising to improve signal-to-noise ratios.
• Expansion of dynamic range to 130 dB, removal of signal amplification circuits, and reduction of excitation voltage.

Main Results:

• Achieved a voltage resolution higher than 1 μV.
• Successfully recorded clear solid tides in low-frequency bands.
• Accurately captured seismic wave strain in high-frequency bands, including S and P wave arrival times and phases.

Conclusions:

• The FPGA-based system offers improved flexibility, efficiency, and observational accuracy for borehole strain measurements.
• The system meets the stringent requirements for geophysical field deformation observations.
• This technology holds significant potential for future geophysical and crust deformation analyses.