摘要：There are complex heterogeneous entities in the underground medium,and the heterogeneous scale has a substantial impact on wave *** this study,we used a set of 11 samples of glass beads as high-velocity heterogeneous bodies to evaluate the impact of such heterogeneous bodies on the propagation of *** vary the heterogeneous scale by changing the diameter of the glass beads from 0.18 to 11 mm while keeping the same volume proportion(10%)of the beads for the set of 11 *** pulse transmission method was used to record measurements at the ultrasonic frequencies of 0.34,0.61,and 0.84 MHz in the homogeneous *** relationship between P-wave fi eld features and heterogeneity scale,P-wave velocity,and the multiple of the wave number and heterogeneous scale(ka)was observed in the laboratory,which has sparked widespread interest and *** scale affects P-wave propagation,and its wave field changes are *** waveform,amplitude,and velocity of the recorded P-waves correlate with the heterogeneous *** the forward scattering while large-scale heterogeneities,noticeable direct and diff racted waves are observed in the laboratory,which indicates that the infl uence of direct and diff racted waves cannot be ignored for large-scale *** relationship between velocity and ka shows frequency dependence;the reason is that the magnitude of change in velocity caused by wave number is diff erent from that caused by heterogeneous *** to the change in the recorded waveform,amplitude variation,or the relationship between the velocity measured at diff erent frequencies and the heterogeneous scale,the identifi ed turning points of the ray approximation are all around ka=*** ka is less than 1,the velocity changes slowly and gradually approaches the eff ective medium *** ray velocity measured for heterogeneous media with large velocity perturbations in the laboratory is signifi cantly smaller than the

摘要：Conventional f-x prediction filtering methods are based on an autoregressive model. The error section is first computed as a source noise but is removed as additive noise to obtain the signal, which results in an assumption inconsistency before and after filtering. In this paper, an autoregressive, moving-average model is employed to avoid the model inconsistency. Based on the ARMA model, a noncasual prediction filter is computed and a self-deconvolved projection filter is used for estimating additive noise in order to suppress random noise. The 1-D ARMA model is also extended to the 2-D spatial domain, which is the basis for noncasual spatial prediction filtering for random noise attenuation on 3-D seismic data. Synthetic and field data processing indicate this method can suppress random noise more effectively and preserve the signal simultaneously and does much better than other conventional prediction filtering methods.

摘要：When a seismic wave propagates through subsurface viscoelastic media,the formation absorbs the high-frequency energy of the seismic wave more strongly than the low-frequency *** the depth and the off set increase,the diff erence between the logarithmic spectral areas with high and low frequencies gradually *** on this seismic wave characteristic,we have developed a novel Q-estimation method based on logarithmic spectral area diff erence of high and low frequencies(referred to as the LSAD_LH method).In this paper,we derive the theoretical relationship between the Q value and difference of logarithmic spectral areas with high and low frequencies and prove the applicability of the LSAD_LH method using a single-layer medium numerical *** verify the sensitivity of the LSAD_LH method to bandwidth selection and noise,we compare the LSAD_LH method with two credible methods—the logarithmic spectral ratio(LSR)and logarithmic spectral area diff erence(LSAD)methods using a synthetic model containing the random *** results demonstrate that the LSAD_LH method is not highly dependent on bandwidth,and in terms of noise immunity,it is signifi cantly better than the LSR method and has the same advantages as the LSAD *** further highlight the advantages of the LSAD_LH method,we apply the LSAD_LH and LSAD methods to the vertical seismic profi ling(VSP)numerical simulation of the multilayer media and the fi eld zero-off set VSP *** application of the two cases proves the applicability of the LSAD_LH method and the accuracy of the high Q-value estimation relative to the LSAD ***,via the transmission coeffi cient,the LSAD_LH method overcomes the weakness of the LSAD method.