Abstract

Sparker and explosive-type marine seismoacoustic signal sources are described, which can be used to solve engineering seismic survey problems in water areas. The problem of surface wave excitation in water area conditions (moreover, in the presence of ice cover) is quite relevant due to the intensive development of surface-wave methods in land seismology. The paper presents the results of an in situ experiment in the ice conditions of Lake Ladoga, devoted to recording seismoacoustic signals in the water column (with hydrophones) and on shore (with a seismic receiver). Processing and analysis of experimental data demonstrated the possibility of applying the coherent integration procedure for a sparker impulse source in order to increase the signal-to-noise ratio of the initial hydroacoustic and seismic data. The waveforms of the signals received in the water column and on shore were obtained as the waves passed through a shore wedge in the presence of sheet ice. The coherence coefficient of signals generated by a sparker and airgun is estimated. The dependence of the signal-to-noise ratio on the number of summed pulses during coherent integration was analyzed. The results point to high quality of the sparker equipment developed at GEODEVICE and demonstrate the possibility in principle of using a sparker to generate seismic waves, including surface ones.

中文翻译：

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冰条件下脉冲地震声源的相干性

摘要

描述了火花和爆炸型海洋地震声信号源，可用于解决水域的工程地震勘测问题。由于陆地地震学中表面波方法的深入发展，在水域条件下（此外，在有冰盖的情况下）表面波激发的问题十分相关。本文介绍了在拉多加湖冰雪条件下进行的原位实验结果，该实验致力于记录水柱（带有水听器）和岸上（带有地震接收器）的地震声信号。实验数据的处理和分析表明，可以为火花脉冲源应用相干积分程序，以增加初始水声和地震数据的信噪比。在有薄冰存在的情况下，当波通过岸楔时，获得了在水柱和岸上接收到的信号的波形。估算了由火花发生器和气枪产生的信号的相干系数。分析了相干积分期间信噪比对求和脉冲数的依赖性。结果表明，GEODEVICE开发的火花机设备质量很高，并且从原理上证明了使用火花机产生包括地表波在内的地震波的可能性。分析了相干积分期间信噪比对求和脉冲数的依赖性。结果表明，GEODEVICE开发的火花机设备质量很高，并且从原理上证明了使用火花机产生包括地表波在内的地震波的可能性。分析了相干积分期间信噪比对求和脉冲数的依赖性。结果表明，GEODEVICE开发的火花机设备质量很高，并且从原理上证明了使用火花机产生包括地表波在内的地震波的可能性。