Design Of Array And Research On Data Processing

The scientist and expert group brought up the suggestion to construct seismic array for monitoring and identifying the faraway underground nuclear test at the Genevese Nuclear Disarmament Negotiation in 1958. Through the development of more than 40 years, the major aims and functions of seismic array observation have many important changes, and many kinds of seismic array are widely distributed in the world. Today, as a kind of monitoring means and geophysical research technique, the construction and study of seismic array is very active in the world. The advantage of seismic array is to weaken the disturbed noises and enhance the earthquake signals by the use of the combination analysis of the signals recorded at all sub-stations of the seimic array, obtaining more information on seismic focus and structure of the Earth interior than the existing seismic observation network.hi this dissertation, the design and construction of seismic array, the data processing techiques for array, and its application to geophysical field and etc are studied further. The theory level of the beamform and the F-K analysis for seismic array is raised. The new method of automatically recognizing the seismic phases from seismogram recorded in the sismic array is put forward. The detection of local scatter sources with the F-K power difference and the method of receiver function for the broadband and the dense seismic array is investigated extensively. Additionally, the characteristics of small earthquakes are studied using the broadband digital data from Shanghai Seismic Array. So, some new research results are obtained as follows.The first, the design of the seismic array. On the basis of the mathematical model about performance of seismic array, the relation between the layout and the performance of seismic array is studied, and hereby the modeling concept of sub-station layout is introduced, which is applied to the construction of Shanghai Seismic Array. According to the natural topographic feature and the purpose of array construction, we designed the most reasonable layout of sub-stations for Shanghai Seismic Array, which results in selecting the reasonable sub-station positions and gaining the good array performance. This paper also points out the importance of array caliberation and it is applied to the caliberation of Shanghai Seismic Array practically.The second, the beamform effect of the seismic array. Because the more satisfied results can't be obtained from the records of lower Signal-to-Noise by the use of the applied beamform analysis, in this paper the three new methods of beamform are given, which are the frequency scanning beamform, the apparent velocity scanning beamform, and the optimized weighted beamform arithmetic with self-adaptive filter. For the first two, the improved correlation method and simple weighted method are adopted, and the new medium-respond vector is introduced. And for the latter, the parameters of self-adaptive filter are designed using the noise's spectrum, and the delay times of all sub-stations are estimated using the optimized weighted arithmetic. The three methods are used for the testing of the earthquake instances, and it shows that, (1) the frenquency scanning beamform only needs short time for analysis and can be used in the real-time processing. The frenquency parameters obtained are helpful to identify phases. (2) The beamform waveforms obtained by use of the apparent velocityscanning beamform preserve all frequency components basically. The azimuth and apparent velocity obtained from processing results can be used to preliminarily determine the location of seismic focus. And the apparent velocities obtained are also helpful to identify phases. (3) The optimized weighted beamform arithmetic with self-adaptive filter has the least error in the delay times of sub-stations, which can be applied to the locating of earthquake.The third, F-K algorithm for seismic array. Here we discuss the theoretic foundation of F-K algorithm and introduce its application. The various wave...