频率—慢度域延拓关键参数优化的鬼波压制方法

鬼波的陷波特性限制了海洋地震资料的有效带宽，因此鬼波压制是海洋资料宽频处理的重要步骤之一。鬼波与一次波的延迟时间和振幅差异系数是鬼波压制的关键参数，两者的精度直接影响处理效果。受崎岖海底、起伏海面及反射层深度变化等因素的影响，实际鬼波参数随空间和时间而变化，导致鬼波压制算子出现误差，无法取得较好的处理效果。为此，以频率—慢度域鬼波压制方法为基础，构建频率—慢度域波场延拓算子，并利用滑动时间窗口降低鬼波参数时变的影响，在滑动时间窗口内用原始地震数据分别加上和减去延拓一次的记录，以运算所得的两个新记录乘积的绝对值之和最小作为度量，交替迭代寻找最优平均鬼波延迟时间和振幅差异系数，进而压制鬼波。斜缆的合成数据和实际资料试算表明，该方法能较好地压制鬼波、拓宽频带，提高地震资料的分辨率。

A ghost wave suppression method based on frequency-slowness domain extension by optimization of key parameters

The notch characteristics of ghost waves restrict the effective bandwidth of marine seismic data, and thus ghost wave suppression is an important step in the broadband processing of marine data. The delay time and amplitude difference coefficient of ghost waves and primary reflections are the key parameters of ghost wave suppression, and the accuracy of the two parameters directly affects the processing results of ghost waves. Due to the influence of rugged seabed, choppy sea surface, varying reflection layer depth, and other factors, the ghost wave parameters fluctuate with space and time in practice, which results in errors in ghost wave suppression ope-rator, and positive processing results cannot be obtained. Therefore, we construct a wave field extension operator based on the ghost wave suppression method in a frequency-slowness domain and use a sliding time window to reduce the influence of time-varying ghost wave parameters. After that, we add and subtract one extension record from the original seismic data in the sliding time window, respectively, take the solved minimum sum of the absolute values of the product of new records as the measurement, and perform alternating iterations to explore the optimal average delay time and amplitude difference coefficient of the ghost waves, so as to suppress the ghost waves. The synthesized data of inclined cables and the actual data calculation show that this method can effectively suppress ghost waves, expand frequency bands, and improve the resolution of seismic data.