未爆弹严重威胁人类的安全,瞬变电磁是一种对其有效的探测方法.探讨了瞬变电磁波场变换理论,实现了对瞬变电磁信号中波场特性的提取,提出了基于虚拟波场波形特征的速度分析反演成像方法,计算了三维数值模型和水槽物理模拟数据的反演结果,取得了良好的成像效果.结合未爆弹探测的工程实例,对瞬变电磁虚拟波场反演成像方法的实用性和有效性进行了验证.研究表明:瞬变电磁虚拟波场反演成像方法能够解决微小低阻异常体精确定位的难题.
Unexploded ordnance today grows into a critical issue of environment, transient electromagnetic is an effective method for its detection. Authors first discussed the theory of transient electromagnetic wave-field transforming, realized the extraction of wave-field characteristics from transient electromagnetic signal, proposed inversion imaging method of velocity analysis based on waveform characteristics of pseudo wave-field, calculated the inversion results of a three-dimensional numerical model data and a physical simulation data, achieved excellent imaging effect. At last, the practicability and effective of the inversion imaging method of TEM pseudo wave-field were proved by the actual exploration of the unexploded ordnance detection. The conclusion show that the inversion imaging method of TEM pseudo wave-field can solve problem of accurate positioning of tiny low resistivity abnormal body.