On the study of electromagnetic prospecting using holographic imaging

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The study was carried out to investigate the applicability of holographic imaging to the high resolution electromagnetic prospecting. I have been studying an applicability of the near-field holography theory to the time domain electromagnetic method. Resolution of the conventional holography depends on the wave length and is expected to same order of it. But, resolution of the near field holography does not relate to the wave length and is expected to less than 1/1000 of it.A high resolution prospecting means obtaining high accurate data. We should increase accuracy of time domain electromagnetic method, which is one for obtaining the data in a field, to increase resolution of the survey. I have been studying feature of the time domain method comparing other electromagnetic method and three dimensional modeling of the time domain data.A frequency domain method, like magnetotelluric method, tend to show less response to an anomaly at depth if low resistivity layer is situating at the surface. The depth of investigation of it tend to be much less than the skin depth of electromagnetic wave, which is usually using estimation of depth of investigation for frequency domain data. In time domain, the response time is only longer and the effect of low resistive layer at surface is less if the data obtain stably during the longer time.I have investigated an effect of three dimensional structure on the resistivity model assumed two dimensional (resistivity structure is uniform at vertical to the section). The anomaly situated beside the section and at the shallower depth is projecting at the deeper part of the two dimensional section. The projection appears in the time domain case similarly and we should develop three dimensional holographic modeling to avoid such effect.