Preliminary study on IP information in signal of extremely low-frequency electromagnetic sounding with artificial high-power fixed source

摘要

In order to overcome the limitation of traditional IP method such as heavy equipment, shallow-depth of exploration, add the complex-resistivity-models into the extremely low frequency electromagnetic sounding with artificial high-power fixed source, to extract the IP information from its signal. Which will develop the application range of IP method; meanwhile develop the precision of frequency sounding. This technical has advantages such as deep-sound-depth, long distance transmission, strong signal, strong Anti-jamming ability and high efficiency. Base on Dias-model, this paper study the forward modeling to IP response with 1D layered model of the earth, with the certain frequency range and exploration depth belong to extremely low-frequency electromagnetic sounding with artificial high-power fixed source. The study results show that: the amplitude of apparent resistivity, phase curve exist obviously anomalies before and after IP parameters to be considered; meanwhile, there are clear relationship between the peak value of the amplitude and phase anomaly ratio before and after IP parameters to be considered to the corresponding frequencies, between the peak values to the depth and thickness of the layer which have IP response also; therefore, the IP information extracting has a good outlook.