Abstract. The ambiguity of geophysical inversions, which is based on a
single geophysical method, is a long-standing problem in geophysical
exploration. Therefore, multi-method geophysical prospecting has become a
popular topic. In multi-method geophysical prospecting, the joint inversion
of seismic and electric data has been extensively researched for decades.
However, the methods used for hybrid seismic–electric data acquisition that
form the base for multi-method geophysical prospecting techniques have not
yet been explored in detail. In this work, we developed a distributed,
high-precision, hybrid seismic–electrical data acquisition system using
advanced Narrowband Internet of Things (NB-IoT) technology. The system was
equipped with a hybrid data acquisition board, a high-performance embedded
motherboard based on field-programmable gate array, an advanced RISC
machine, and host software. The data acquisition board used an ADS1278
24 bit analog-to-digital converter and FPGA-based digital filtering
techniques to perform high-precision data acquisition. The equivalent input
noise of the data acquisition board was only 0.5 µV with a sampling
rate of 1000 samples per second and front-end gain of 40 dB. The multiple
data acquisition stations of our system were synchronized using
oven-controlled crystal oscillators and global positioning system
technologies. Consequently, the clock frequency error of the system was less
than 10−9 Hz at 1 Hz after calibration, and the synchronization accuracy
of the data acquisition stations was ±200 ns. The use of
sophisticated NB-IoT technologies allowed the long-distance wireless
communication between the control center and the data acquisition stations. In
validation experiments, it was found that our system was operationally
stable and reliable, produced highly accurate data, and it was functionally
flexible and convenient. Furthermore, using this system, it is also possible
to monitor the real-time quality of data acquisition processes. We believe
that the results obtained in this study will drive the advancement of
prospective integrated seismic–electrical technologies and promote the use
of IoT technologies in geophysical instrumentation.
Research on the Gravity Disturbance Compensation Terminal for High-Precision Position and Orientation System
