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图像测量中光斑尺寸优化及性能分析 被引量:16
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作者 周锐 房建成 祝世平 《仪器仪表学报》 EI CAS CSCD 北大核心 2000年第2期177-179,210,共4页
该文从数理统计学的角度 ,并在假设光斑能量和探测器噪声分别为高斯分布和泊松分布情况下 ,对图像测量中 CCD敏感面上光斑图像的位置估值性能进行了深入分析 ,并从统计意义上得出了光斑图像的位置估值性能与光斑尺寸之间的定量关系 。
关键词 图像测量 图像光斑 形心估值 尺寸优化 性能分析
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Continuous time-varying Q-factor estimation method in the time-frequency domain
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作者 Wang Qing-Han Liu Yang +1 位作者 Liu Cai Zheng Zhi-Sheng 《Applied Geophysics》 SCIE CSCD 2020年第5期844-856,904,共14页
The Q-factor is an important physical parameter for characterizing the absorption and attenuation of seismic waves propagating in underground media,which is of great signifi cance for improving the resolution of seism... The Q-factor is an important physical parameter for characterizing the absorption and attenuation of seismic waves propagating in underground media,which is of great signifi cance for improving the resolution of seismic data,oil and gas detection,and reservoir description.In this paper,the local centroid frequency is defi ned using shaping regularization and used to estimate the Q values of the formation.We propose a continuous time-varying Q-estimation method in the time-frequency domain according to the local centroid frequency,namely,the local centroid frequency shift(LCFS)method.This method can reasonably reduce the calculation error caused by the low accuracy of the time picking of the target formation in the traditional methods.The theoretical and real seismic data processing results show that the time-varying Q values can be accurately estimated using the LCFS method.Compared with the traditional Q-estimation methods,this method does not need to extract the top and bottom interfaces of the target formation;it can also obtain relatively reasonable Q values when there is no eff ective frequency spectrum information.Simultaneously,a reasonable inverse Q fi ltering result can be obtained using the continuous time-varying Q values. 展开更多
关键词 local centroid frequency local time-frequency transform Q-factor estimation shaping regularization
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