During seismic data acquisition, a high-sensitivity geophone with a high inherent frequency can increase high frequency energy by suppressing low frequency signals. This could cause a worse response at low frequencies...During seismic data acquisition, a high-sensitivity geophone with a high inherent frequency can increase high frequency energy by suppressing low frequency signals. This could cause a worse response at low frequencies. If the advantages of high-sensitivity data and conventional data are combined, the effective bandwidth will be broadened. Considering this, we propose a partial frequency band match filtering method which can combine the advantages of both high frequency and conventional frequency ranges. By introducing Ricker wavelets with different dominant frequencies and amplitudes, we established a theoretical model which possesses characteristics of both types of seismic data and demonstrates the feasibility of the partial frequency band match filtering method. A test using single shot records shows the effectiveness of this method for widening the effective frequency band.展开更多
Based on the principle of impedance mismatching,the performance of rigid vibration isolation mass in impeding vibration wave propagation was discussed from the perspective of wave approach.Based on FEM,the influence o...Based on the principle of impedance mismatching,the performance of rigid vibration isolation mass in impeding vibration wave propagation was discussed from the perspective of wave approach.Based on FEM,the influence of its weight as well as the cross-section shape parameters on the isolation performance of rigid vibration isolation mass was studied through numerical simulation.The results show that rigid vibration isolation mass can effectively impede the propagation of the medium and high frequency vibration waves,and the heavier the vibration isolation mass,the better the isolation performance.For low frequency waves,the vibration isolation effect is not so obvious;for a rectangular vibration isolation mass,the isolation performance could be effectively improved by increasing the cross-section height and reducing the cross-section width.A useful reference was provided for the application of rigid vibration isolation masses to the vibration isolation and noise reduction of ship structure.展开更多
In view of the airborne application characteristics such as flexible flight, large error of altimeter, large initial error of inertial navigation system, etc., a new terrain matching system architecture which is suita...In view of the airborne application characteristics such as flexible flight, large error of altimeter, large initial error of inertial navigation system, etc., a new terrain matching system architecture which is suitable for airborne application is presented. The key techniques in terrain matching system realizing process including system workflow, terrain matching algorithm and selection criterion of matching region are expatiated. The experimental results prove the rationality and feasibility of the proposed solution.展开更多
基金financially supported by the National Natural Science Foundation of China(No.41104072)College Students Science and Technology Innovation Activity Plan in Zhejiang Province(No. 2012R401214)
文摘During seismic data acquisition, a high-sensitivity geophone with a high inherent frequency can increase high frequency energy by suppressing low frequency signals. This could cause a worse response at low frequencies. If the advantages of high-sensitivity data and conventional data are combined, the effective bandwidth will be broadened. Considering this, we propose a partial frequency band match filtering method which can combine the advantages of both high frequency and conventional frequency ranges. By introducing Ricker wavelets with different dominant frequencies and amplitudes, we established a theoretical model which possesses characteristics of both types of seismic data and demonstrates the feasibility of the partial frequency band match filtering method. A test using single shot records shows the effectiveness of this method for widening the effective frequency band.
基金Supported by the Shipbuilding Industry of National Defense Science and Technology Research Projects in Advance under Grant No.153010110031
文摘Based on the principle of impedance mismatching,the performance of rigid vibration isolation mass in impeding vibration wave propagation was discussed from the perspective of wave approach.Based on FEM,the influence of its weight as well as the cross-section shape parameters on the isolation performance of rigid vibration isolation mass was studied through numerical simulation.The results show that rigid vibration isolation mass can effectively impede the propagation of the medium and high frequency vibration waves,and the heavier the vibration isolation mass,the better the isolation performance.For low frequency waves,the vibration isolation effect is not so obvious;for a rectangular vibration isolation mass,the isolation performance could be effectively improved by increasing the cross-section height and reducing the cross-section width.A useful reference was provided for the application of rigid vibration isolation masses to the vibration isolation and noise reduction of ship structure.
基金This work was supported by the National Key Basic Research and Development （973） Program of China （Grant No. 2010CB731806） and Aeronautical Science Foundation of China （Grant No. 20100818018）.
文摘In view of the airborne application characteristics such as flexible flight, large error of altimeter, large initial error of inertial navigation system, etc., a new terrain matching system architecture which is suitable for airborne application is presented. The key techniques in terrain matching system realizing process including system workflow, terrain matching algorithm and selection criterion of matching region are expatiated. The experimental results prove the rationality and feasibility of the proposed solution.
