Seismic wave velocity is one of the most important processing parameters of seismic data, which also determines the accuracy of imaging. The conventional method of velocity analysis involves scanning through a series of equal intervals of velocity, producing the velocity spectrum by superposing energy or similarity coefficients. In this method, however, the sensitivity of the semblance spectrum to change of velocity is weak, so the resolution is poor. In this paper, to solve the above deficiencies of conventional velocity analysis, a method for obtaining a high-resolution velocity spectrum based on weighted similarity is proposed. By introducing two weighting functions, the resolution of the similarity spectrum in time and velocity is improved. Numerical examples and real seismic data indicate that the proposed method provides a velocity spectrum with higher resolution than conventional methods and can separate cross reflectors which are aliased in conventional semblance spectrums; at the same time, the method shows good noise-resistibility.

地震波速度是地震数据最重要的处理参数之一，它也决定了成像的准确性。常规的速度分析方法包括扫描一系列相等的速度间隔，通过叠加能量或相似系数产生速度谱。然而，在该方法中，相似谱对速度变化的敏感性较弱，因此分辨率较差。为了解决上述传统速度分析方法的不足，提出了一种基于加权相似度的高分辨率速度谱获取方法。通过引入两个加权函数，可以提高时间和速度上相似谱的分辨率。数值算例和真实的地震数据表明，所提出的方法提供的速度谱比常规方法具有更高的分辨率，并且可以分离出在常规相似谱中混叠的交叉反射器。同时，该方法具有良好的抗噪声性。