SEDIS IV型短周期自浮式海底地震仪数据校正方法

The seismic data corrections of short period auto-floating ocean bottom seismometer

利用15台SEDISIV型短周期自浮式海底地震仪在南海中、北部地壳深部结构调查中所获得的资料,探讨了海底地震仪数据校正的方法和校正后的效果,结果表明:使用该地震仪所获得的原始资料经过放炮时间、炮点坐标数据局部化、海底地震仪位置误差以及记录时间漂移4方面的校正后,数据更趋合理,误差显著降低。放炮时间的校正消除了时钟漂移和时间延迟的误差;炮点坐标数据局部化处理消除了炮点位置整体趋势性偏移的现象;试错法进行位置误差和记录时间的精细校正时,时间漂移的校正量值约为几个到十几个毫秒,位置校正的量值仅在几米到数百米之间,实测数据所绘曲线的形态和位置都与理论曲线十分吻合,可见校正后误差显著降低。

The Second Institute of Oceanography, SOA, has just carried out a marine seismic survey successfully for crustal and mantle structure in the middle-northern margin of the South China Sea, using 15 sets of ocean bottom seismometer （OBS） of short period auto-floating type imported from GeoPro GmbH, Germany. The seismic data correction methods are described in detail, including shot time, shot location , OBS coordinate and recording time .The result shows that several kinds of errors are reduced noticeably, establishing the base of accurate inversion ： the shot time correction eliminates clock drift of the computer and delay time; developed least square regression, trend migration of shot location data is diminished; curve of primary arrival matches well with the theoretical curve as an application of trial-and-error procedure, at the same time, actual time and location approach to the truth better.