Study Of Wireless Synchronization In Shallow Seismic Exploration

As the main equipment for seismic exploration, seismic instrument is the core of seismic data acquisition and the key point to obtain the seismic data with high SNR, high-resolution, high-fidelity in the field. Currently wired telemetric seismograph has been widely used as mainstream equipment, and has achieved very good results in various engineering geological evaluation and exploration areas, however, along with the continuous improvement of seismic exploration technology, and more and more poor seismic exploration environment, the overall project volume and the area also expanded, making the current mainstream cable telemetric seismograph is difficult to meet this demand to a certain extent, considering these disadvantages and giving full consideration to the construction of complex terrain conditions, and further improving the construction efficiency, it makes wireless telemetric engineering seismograph to be a trend in the technical field. Based on an overall consideration of the research status in this field at home and broad, mature products has not yet emerged, so the wireless telemetric shallow seismograph has broad application prospects and market value in geophysical exploration's aspect at home and abroad.This paper combines practical application, system design includes data acquisition and wireless transmission .The paper emphatic research wireless transmission system. To improve the accuracy of wireless time synchronization, paper focuses on the target of its structure, time synchronization error sources, improve time synchronization precision measures, the design of hardware and software .Meanwhile ,the paper designs a complete system noise control ,enhances the effective resolution ADC,and controls the system noise within 400 LSB (119.2 muon V). At the same time ,designs the nRF905 chip close (800 metre) wireless data transmission which can realize the seismic data wireless transmission between acquisition card to acquisition stand. Using the model that combines host and slave improves accuracy of the system clock synchronization and the synchronous accuracy reached 0.25 atus.It can meet the requirements of seismometers acquisition system, realized the engineering seismometers high-speed data acquisition and wireless transmission system development. Especially data sampling accuracy and system clock synchronization achieved good technical indicators.After the synchronization protocol and method is successfully discussed in this paper, the wireless data collection technology will be applied to the engineering geology, which would break the traditional wired transmission, simplify the wiring, improve the work efficiency and shorten one-third time of the cable way.The wireless time synchronization protocols is proposed to solve the current problem of large time errors in the engineering geophysical equipment. This technology will definitely have a bright prospect.