Induced polarization (IP) is the primary method used for the exploration of various metal minerals and for groundwater prospecting. The function and performance of IP instruments have significantly improved over the years; however, most instruments still have some shortcomings, such as limited data acquisition accuracy, large size, separate transmitter and receiver, complex human-computer interaction, difficult networking and remote monitoring. In this study, a novel multifunctional IP instrument system is developed based on remote wireless communication technology, which has high data acquisition accuracy, small size, lightweight, flexible and diverse functions (single instrument can realize transmission and reception), remote wireless real-time monitoring, and convenient networking of multiple instruments. We independently designed a high-precision data acquisition circuit with a noise floor of 0.29 µV and a 5-fold increase in acquisition accuracy. With an intelligent power module as its core, the designed transmitter has a maximum output power of 6 kW and can transmit stepped waves and rectangular waves of various frequencies and duty cycles. We also developed a host computer program on an Android mobile terminal based on Java, which allows users to wirelessly control the instrument through mobile phones over Wi-Fi networks. In addition, we introduced the Internet of Things technology in geophysical instruments and designed a real-time remote monitoring system for data quality and multiple instruments networking scheme based on the short message service of the BeiDou navigation satellite system and cloud service platform. Multiple tests revealed that the proposed instrument meets the requirements of field exploration. INDEX TERMS Cloud service platform, data acquisition, induced polarization instrument, Wi-Fi communication.

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.

Abstract. Seismic exploration equipment has developed rapidly over the past few decades. One such piece of equipment is a centralized seismograph, which plays an important role in engineering, so improving its performance is of great scientific significance. In this research, the core part of general seismic-data acquisition devices is packaged to develop a centralized seismic-data acquisition system (named CUGB-CS48DAS) that has independent operating ability and high scalability, which can be used for seismic exploration in various engineering uses. Furthermore, by extending and modifying the acquisition circuit and corresponding software, the function of electrical method data acquisition has also been achieved. Thus, the proposed CUGB-CS48DAS makes it possible for joint exploration of seismic and electrical data in a single acquisition station, which is implicitly of great convenience in engineering prospecting as well as a solution to reduce the ambiguity problem. The low power-consumption computer of the system comprises a 24 bit Σ modulation A/D converter and 48 sampling channels with an optional sampling rate of 50 Hz to 64 kHz. With regard to the host computer, the architecture of the control software is smart, and it can integrate the multiple functions of data acquisition, preprocessing, and self-testing. To complete the networking ability and remote monitoring of this proposed system, the technology of the narrow-band internet of things (NB-IoT) was introduced and tested. Field experiments were implemented to prove that the system is stable and convenient to use, and the performance could meet the demand of high-precision joint exploration.

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Abstract. The non-uniqueness 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, and hybrid seismic-electrical data acquisition system using advanced Narrow Band-Internet of Things (NB-IoT) technology. The system was equipped with hybrid data acquisition board, a high-performance embedded motherboard based on field-programmable gate array and 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 @ 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 control center and data acquisition stations. In validation experiments, it was found that our system was operationally stable and reliable, produced highly accurate data, and 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.