主动源勘探中震源编码与解码方法

依据人工主动震源的可控性,引入通讯中的编码原理,采用震源编码技术能够有效提高小当量人工震源的探测深度和信号接收距离。笔者分析研究了主动源勘探中的震源编码与解码方法,主要做了以下工作:①分析研究了震源信号自相关函数的基本性质,探讨了利用自相关函数峰值间的零值区进行信号检测的可能性,研究表明编码方法能够通过相关增加有效信息的检测范围,提高监测能力;②研究了震源编码的三种基本方式,分析了它们的旁瓣压制效果,通过不同激发能量的源在不同时刻重复激发建立编码震源,信号能够在相关峰值和相关旁瓣间有效检测出;③探讨了迭代相关法解码的基本原理,编码方法能够大幅度提高地震探测能力,利用小能量震源获得大的探测距离和高分辨率,具有很强的抗干扰能力。

A study of encoding and decoding method in active seismic source exploration

According to the repeatability and controllability of artificial active source, encoding seismic source can be used effectively to improve the capability of artificial source exploration depth and detection distance. In this paper, the authors studied the encoding and decoding method of active seismic source exploration, and mainly did the following work：①the analysis of the basic principles of en-coding seismic source. The coded method can increase the range of the target and reduce side-lobe energy with correlation;②the study of three source encoding methods, and make the comparison. The authors have designed coded source which can be fired repeatedly in different time intervals with different energies, and coded seismic source can reduce autocorrelation side-lobes. Signals can be detected with better sensitivity in the time interval after the first autocorrelation peak and before the first periodic side-lobe;③ the study of the principle of iterative correlation method for decoding. The encoding method can significantly improve the seismic exploration capability. It is proved that researchers can obtain a large detection range and high resolution using encoding method with small energy source.