【摘要】 电磁测深方法可分为频率域测深和时间域测深两大类.时间域测深主要是在一次激励场结束后,观测二次涡流场.对于频率域电磁测深方法,研究问题时仅考虑边界条件即可,但对时间域方法,不但要考虑边界条件,还要考虑初始条件,所以时间域的研究往往比频率域的研究要复杂得多.在以往的时间域方法中,通常使用阶跃波作为激励源,这主要是由于阶跃波激励完成后,有充裕的时间间隙可以观测感应二次场.但由于阶跃波的时间域电磁响应的复杂性,往往采用分时段(分区间)的处理方式,分为远区(早期)、近区(晚期)、过渡区(过渡期)等方式.本文介绍一种利用δ单脉冲函数的激励源的时间域电磁响应实现电磁测深的方式.它不需要将时间域分成多个区段,且可以借助任何的第三方激励源来进行激励.观测电磁响应也不需要在激励结束后进行.更多还原

【Abstract】 We often divide the electromagnetic sounding methods to frequency domain and time domain.Time domain electromagnetic sounding method surveys the second field after the first field having gone.We just need to consider the boundary condition for the frequency domain electromagnetic sounding.But for the time domain method,we should consider the original condition except the boundary condition.So it is more complex for the study in the time domain than that in the frequency domain.In general,we use the step wave as the active source because of the enough time interval of surveying the second field.We often split the time into early part,transition part and late part.And the problems are resolved separately because of the complex electromagnetic response of the step wave active source. We introduce a new electromagnetic sounding method by using S function active source in this paper.We don’t need to split the time to some segments.And we can use the third part active source to activate the object.We can survey the electromagnetic response at the mean time of activating.更多还原