Research On Low-power Portable Broadband Seismic Observation System Based On Mobile Communication

In the natural seismic observation research,the portable broadband seismic observation research is an effective supplement to the fixed seismic network.In areas that are difficult to cover or unevenly covered by the fixed seismic network,portable broadband seismic observations can more effectively monitor earthquake events and more accurately record seismic ambient noise.It can make up for the lack of earthquake monitoring in the corresponding area and obtain more detailed information of underground structures.The key to portable broadband seismic observation research is the broadband seismic observation instrument system.In order to meet the demand for instruments for portable broadband seismic observation research in our country and get rid of the dependence on imported instruments,we need to independently develop portable broadband seismic observation instruments.Based on the previous research of our research group,aiming at the characteristics of portable broadband seismic observation,this paper proposes an overall design scheme of a low-power portable broadband seismic observation system based on mobile communication.A prototype system was developed,and tests and application experiments were carried out to verify the validity and reliability of the instrument scheme.The research contents of this thesis are as follows:(1)The main broadband seismic instruments used for natural seismic observation at home and abroad are investigated.On this basis,the portable broadband seismic observation method is studied,and the special requirements of the portable broadband seismic observation for the instruments are analyzed.Aiming at these requirements,an overall design scheme of a portable broadband seismic observation instrument is proposed.(2)According to the design principle of the overall scheme,the high-precision and low-noise acquisition technology,low-power power management technology,seismometer calibration and testing technology,high-efficiency data compression and transmission technology,and Wi-Fi wireless monitoring technology involved in the portable broadband seismic observation system are respectively studied.In the research of high-precision and low-noise acquisition technology,the least square method is used to optimize the AD acquisition accuracy and greatly reduce the indication error of AD acquisition.In the research of low-power intelligent power management technology,the ultra-low-power microcontroller STM8L151C6 is selected as the main control chip.The power supply system management circuit includes a voltage and current monitoring unit,a battery charging and power switching unit,a DC-DC conversion unit,a sensor power supply circuit,and a switch circuit.These realize the low-power intelligent management of the power supply system and greatly improve the efficiency of the power supply system.In the research of seismometer calibration and testing technology,a universal broadband seismometer calibration test device built in the broadband seismograph is designed based on FPGA,which makes the calibration and testing of seismometers convenient and easy to operate,simplifies the process of portable broadband seismic observation operations,and improves the overall integration of the observation system.In the research of high-efficiency data compression and transmission technology,the Mini SEED format is selected as the file format for system data recording and data transmission,and the high compression ratio of data storage saves storage space and data transmission bandwidth.In the research of Wi-Fi wireless monitoring technology,a Wi-Fi wireless monitoring software based on i OS system terminal has been developed.In the Ad-Hoc wireless networking mode established by the Wi-Fi module in the broadband seismograph,the i OS system terminal is connected to the wireless network of the instrument to realize the parameter setting and operation status view of the observation system.It improves the efficiency of portable broadband seismic observation system deployment and makes inspection more convenient.(3)Aiming at the demand of remote monitoring of portable broadband seismic observation,a remote monitoring scheme based on mobile communication is proposed.Huawei MU609 module is selected to build a mobile communication unit.The software design of mobile communication based on embedded Linux operating system is completed,including driver integration,dial-up software porting and configuration,and application design.Finally,the low-cost and high-efficiency monitoring of the operation status of the portable observation system is realized by means of text messages and emails.At the same time,the remote state monitoring method based on cloud server is studied to realize the monitoring of the quality of the data collected by the portable observation system.(4)The key performance parameters of the self-developed portable broadband seismic observation instrument GEIBSR are tested and analyzed.Compared with foreign advanced broadband seismographs REFTEK-130-01 and Q330 HRS,GEIBSR has great advantages in seismometer control,Wi-Fi wireless status monitoring,remote status monitoring and data quality monitoring,and is more suitable for field portable broadband seismic observation research.The acquisition performance of GEIBSR was further tested with REFTEK-130-01 and Q330 HRS.The analysis of the test results shows that the consistency of the collected data is all above 0.9,even close to 1.The South China portable broadband seismic observation experiment demonstrates the performance advantages of GEIBSR in portable seismic observation.