The Development Of Seismic Signals Acquisition System Based On MEMS Seismometer

Detection and analysis of seismic signals can help people understandearth's structure and predict earthquake disasters. It is difficult to detectseismic signals accurately because its frequency is too low and energy is tooweak. So it is necessary to design a high-performance seismic signalsacquisitionsystem.This theses introduces the design of a tri-axis seismometer based onMEMS technology, aims to overcome the disadvantages of traditionalseismometers, such as large volume and narrow band. In the design,1221x-002ischosentodetectearthquake,andsubsequentsignalconditioningcircuits are designed to improve signal to noise ratio, including amplifying,filtering and DC removing. By reasonable assembly and testing, aseismometerwiththreesensingdirectionsis finallydeveloped.ThenDT9820,a data acquisition board with 24 bit resolution, is chosen to convert theseismic data. Based on the board, an acquisition and processing software isprogrammed with Visual C++ 6.0. The main functions of the developedsoftwareincludedataacquisition,curveportray,storingofPSNfilesandFFTspectrumanalysis. Many methods are used to improve the system's real-time property andreliability. Power saving and anti-interference are introduced to optimizehardware performance. Reasonable allocation of buffers, utilization ofWINDOWS message mechanism and GPS module are also applied in theacquisitionandprocessingsoftware.The results of experiments prove that the developed system can meet theneed of real-time data acquisition and signal analysis. The saved data can beread by the WinQuake, a professional seismic signals processing software.Furthermore, the designed software is full of friendly user interface andstableperformance.