SEDIS IV型短周期自浮式海底地震仪数据校正方法

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

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.