摘要:
在海洋环境下,OBS(海底地震仪)投放后,由于潮汐、涌浪以及海流等因素的影响而漂移,OBS资料处理的首要任务就是进行OBS的二次定位。深水环境下一般使用直达波二次定位技术,直达波定位的传统方法是采用网格节点法计算直达波线性动校正,计算工作量非常大。列举了OBS落点漂移的多种情形,模拟了不同情况下直达波的线性动校正曲线,分析了影响线性动校正曲线变化的各个因素,建立了判断落点方向的标准,提出了十字交叉法反演OBS落点位置,对实测资料进行落点位置反演,获得了准确的定位结果。此方法明显减少了计算工作量,可以快速获得准确的OBS落点位置。
Abstract:
After being released from the vessel, the OBS begins falling towards the seafloor. There is also lateral drift during its falling. Therefore, before any further processing to be done, it was indispensably needed to relocate OBS. The first arrival time was commonly used in relocating technology, especially for deep water. The traditional method was using mass grid computing of the LMO of the first arrival time to find the grid whose LMO is flat. It is a work of time consuming In this paper, we made a series of direct wave time modeling for several cases of relocation. It is a work of time consuming. Based on the review of the traditional method, we presented a new cross-relocating method to estimate the drifting distance in this paper. The new method was used to relocate the OBS in 2012. The results were satisfactory. Comparing to the traditional method, the computing work load was much reduced.
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