The Study Of Mini-Sosie Seismic Prospecting Technology Based On Pseudorandom Code

Mini-sosie seismic prospecting which is flexible , lightweight,high-resolution and non-destructive occupys the important position of tamping the earthquake source. The mini-sosie seismic prospecting system is ideal seismic survey equipment to carry out in the city which can suppress interference and improve signal noise ratio in seismic records ,minimizing the damage and impact on the environment , building rammed-based procurement and maintenance easier, reducing exploration costs and raise construction speed. As the source for the seismic exploration, it generates the pseudo-random impact signals depending on changing the frequency of rammer, uses the relevant superposition method to produce records of earthquake.To find the impact of the measured correlation signal from the positive image and signal to noise ratio sidelobe factors, MT-72FW rammer signal source is analyzed.Mikasa's MT-72FW rammer need manual control operations to generate seismic wave source, though the limits of manual operations will result the non-random in the seismic waves , Therefore, the signal on the lead is vulnerable to external environment, Sidelobes result is clear, serious related noise, make noise ratio decreased dramatically. By using software to process the data ,the waveform can be acquired and analyzed , Conclusion is non-improved MT-72FW has a really bad effect.The paper improved Mikasa's MT-72FW rammer to solve the above problem, this design has its own unique ideas and innovation, adding pseudo-random coding technique to the design of Mini-sosie seismic prospecting, Mainly using the principle of pseudo-random coding technique carry out the research from the circuit design and software aspects. The randomness of pseudo-random coded signal is very good and can be controlled by manual, autocorrelation function is very close to the one of white noise, finding a breakthrough of research for the mini-sosie seismic prospecting.After analyzed the principle of pseudo-random coding technique and compared the pseudo-random coding with the non-pesudo-random coding techniques, Obtained the conclusion that using pseudo-random coding techniques to improve practical conclusions rammer is available. First of all , improved the external circuits of hardware system, and the design of the external circuit is simple and practical, it will not increase the basis of the original system load. Simple interactive interface, making it very convenient in operation together. The other is on the software aspects , controlliing the generated pseudo-random code, simulating the program on the platform of Keil , the simulation results basically achieved the desired results.In the same time of simulating the whole result of research and design via software, maked the true improved rammer,and done lots of experiment. The paper give the field test results,and contrast the result with the origin rammer , the results show the Lobe very small, less correlated noise, high signal to noise ratio obtained. The result indicates the theory is in accordance to the reality, and the correctness of the design.The thesis is divided into six chapters, starting with shortcomings of the mini-sosie seismic prospecting in the structure . and then offered the solutions and designs by researching the theory of pseudo-random code .The first chapter principally describes the history of the Impact source technology, which detailly elaborate significance of this study and the contents,it also Provides Mikasa's MT-72FW rammer effect the appearance of maps and map explorationThe second chapter describes the basic idea of impact source seismic exploration. primary discusses the principles of seismic exploration, seismic impact source principle and the impact source seismic reflection wave theoryThe third chapter has studied the application to pseudo-random coding technique in impact source, has found how to design and transform the impact source based on the records obtained theory, and has compared non-random coding techniquesThe fourth chapter designed the signal unit of pseudo-random code impact source . MT-72FW impact source is improved Using pseudo-random coding principle . this part is the core of this article .This chapter designed the overall structure of the system,and gave the hardware design and software design. IRandomly coded pulse signals generated was real time simulated in the KeilμVision3 high time precision of random code pulse signal was got.The fifth chapter analyzed the experimental results . Experimental results show that the theory and practice to achieve a good agreement.The sixth chapter is a summary text.And gives the next step's work.