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在海上实施三维地震探测过程中,人工震源枪阵中心与船上GPS的距离及地震探测作业中的船行方向造成炮点实际位置与预设位置有一定偏差;自由落体投放的OBS由于海流的影响会偏离原定设计位置(投放点),因此,炮点与海底地震仪(OBS)的位置校正是三维地震结构研究中的基本环节.本文利用艏向信息校正了炮点位置;采用蒙特卡洛和最小二乘法方法对海底地震仪的位置进行了校正,并探讨了直达水波曲线特征.结果表明OBS位置一般偏离设计点1km左右,其误差范围在20m以内,校正后的OBS记录剖面展示了真实的记录情况.该研究结果为下一步西南印度洋的三维层析成像研究提供了坚实数据基础,同时为今后南海的三维深部地壳结构探测提供经验与借鉴.
During the implementation of 3D seismic exploration at sea, the distance between the center of artificial gun array and the GPS on board and the direction of the ship during the seismic exploration operation cause some discrepancies between the actual position of the shot and the preset position. Due to the influence of ocean currents, Therefore, the position correction of shot and seabed seismograph (OBS) is the basic link in the research of 3D seismic structure.In this paper, the shot position is corrected by using the directional information, the Monte Carlo and Least squares method was used to correct the position of the seabed seismometer and the characteristics of the direct wave curve were discussed.The results show that the OBS position is generally about 1km away from the design point and the error range is within 20m.The corrected OBS record shows the true The results of this study provide a solid foundation for the next three-dimensional tomography study of the Southwest Indian Ocean and provide experience and reference for the future exploration of three-dimensional deep crustal structures in the South China Sea.