【摘要】 单道反射地震以其配置灵活、操作简单、高效经济的优势,在海洋区域地质调查、近海工程物探等领域得到了广泛的应用.利用海上作业前期对单道地震系统试验的数据进行分析,获得船舶等背景噪声的频率特征,为室内资料处理提供可靠依据,旨在最大限度地保留有效信号并压制船舶等背景干扰,提高地震资料处理的效率和剖面的质量.根据实际处理结果,得到2点认识:(1)通常情况下,海洋地震勘探中船舶等背景干扰信号的频率低于200 Hz,而电火花震源的主频在200 Hz以上,二者在频域可分开;(2)地震记录的高低频信号各有用处,野外作业时应尽可能采集背景噪声数据,为室内资料处理提供依据,以免去除噪声的同时滤除了有效信号.最后基于分析处理过程中遇到的问题,进一步提出海洋勘探过程中船舶等背景噪声的调查设计,旨在研究船型、航速、水听器拖曳长度等对背景噪声在地震记录中的特征有何影响以及如何控制船速及水听器拖曳长度来使得野外原始记录的信噪比达到最大.更多还原

【Abstract】 The seismic exploration of single-channel is widely used in marine regional geological survey and coastal engineering geophysical prospecting with its layout flexibility,easy operation,and also the high-efficient and lowcost. The author analyze the seismic data acquired by single-channel seismograph without the sparker by the means of FFT( fast fourier transform) and get the spectrum of noise record,and then apply the analysis result to seismic data processing aiming at suppressing the background noise and reserve the useful signal maximumly,and also improving the efficiency of seismic data processing. According to the processing result,the author get two cognition:( 1) In general,the frequency of the background noise during marine seismic prospecting is below 200 Hz and the basic frequency of sparker is usually above 200 Hz,which can be separated on the frequency domain.( 2) The high and low frequency signal in seismic record have their own use,the field staff have to acquire the data of background noise as it can provide information for indoor data processing lest filtering the useful signal when deal with the interference. At last,the author put forward the project of surveying the noise made by research vessel et al,view to study how the different type of ship,navigational speed and drag length of hydrophone influence the feature of background noise in seismic record and figuring out how to control the speed and drag length to maximize the SNR( signal to noise ratio) of original seismic record.更多还原