叠前多道子波处理

子波处理可分为确定性和统计性两种方法.在实际应用中,纯确定性的子被处理方法并不能取得好效果.本文研究了确定性与统计性相结合的方法:(1)用叠前多道自相关平均的方法来估算子波自相关函数,使反射时间序列更符合平稳随机的假设;(2)用指数加权法估算子波,使子波不再受最小相位假设的限制;(3)根据上述多道自相关平均、子波及零相位期望输出计算子波处理算子,处理实际资料时对噪声具有自适应能力,既提高了分辨率,又能增加信噪比。对于地表条件复杂的陆上资料,我们还研究了地表一致性子波处理方法。对共炮点道集和共检波点道集分别计算多道自相关平均,估算每道的子波,最后一次实现子波处理。

MULTICHANNEL WAVELET PROCESSING BEFORE STACK

There are two techniques in wavelet processing, namely, the determinative and the statistical. In practice, the purely determinative technique couldn' t get a good result under the condition of known wavelet. In this paper, a method of combining the technique of determinative with that of statistical was developed. Steps of its implementation are as the follows:1. to estimate the wavelet autocorrelative function by the average multichannel autocorrelation before stack so as to make the reflection time sequence to be more fitted to the stationary random assumption.2. to estimate the wavelet by using the technique of exponential weighting, thus, the assumption of the wavelet should be in its mininum phase is no more in necessity.3. to calculate the operator used in wavelet processing by use of the average multichannel autocorrelation, the wavelet and the zero-phase expected output. The calculation itself has the capability of self-adaption, hence, not only the resolution but also the S/N ratio could be improved.As for the data obtained from the complex land surface, a method of wavelet processing for solving the problem of surface consistent was developed :to calculate the average multichannel autocorrelation for the common-shot point gather and the common geophone gather separately, then, to estimate the wavelet for each channel, and finally, to carry out and implement the wavelet processing at a stroke.