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成像地球内部介质结构及其动态变化是地球物理学家的主要任务。相对于对地球介质静态结构的认识,对于地下介质性质随时间变化的了解明显不足。近年来随着观测资料的增加,已经开始利用重复地震和噪声等震源研究地下介质变化。受到源位置和时间等因素制约,基于地震和噪声等被动震源的观测结果的时间和空间分辨率有限。利用人工震源主动向地下发射地震波,进行地下介质监测自然成为一个重要的发展方向。系统地介绍了国内外利用人工震源进行不同尺度地下介质变化监测的研究,分析了不同震源的优缺点。根据分析和对比结果,认为在进行地下介质变化研究方面,气枪震源要优于其他震源。还介绍了相关的数据处理方法,包括互相关延时估计,尾波干涉和信号叠加等。目前用于大尺度地下动态监测的震源,接收和数据处理等主要技术已经基本发展成熟,利用人工震源进行地下介质大尺度监测成为可能,相关研究在减轻自然灾害和资源探查等领域具有广阔的应用前景。
Imaging the Earth’s internal media structure and its dynamic changes are the main tasks of geophysicists. Relative to the understanding of the static structure of the Earth’s medium, there is a clear lack of understanding of the nature of the underground medium over time. In recent years, with the increase of observation data, the use of repetitive earthquakes and noise sources has begun to study the change of underground medium. Due to the constraints of source location and time, the time and spatial resolution based on the observations of passive sources such as earthquake and noise are limited. The use of artificial seismic sources to actively launch underground seismic waves, underground media monitoring of natural become an important direction of development. This paper systematically introduces the domestic and international studies on the monitoring of underground medium change with artificial sources at different scales and analyzes the advantages and disadvantages of different sources. According to the results of analysis and comparison, it is considered that the airgun source is superior to other sources in the research of underground medium change. Also introduced the relevant data processing methods, including cross-correlation delay estimation, coda interference and signal overlay. At present, the main technologies of seismic source, reception and data processing for large-scale underground dynamic monitoring have been basically developed. It is possible to use artificial seismic source to carry out large-scale monitoring of underground medium. The related research has broad application in mitigation of natural disasters and resource exploration prospect.