The Effection of Electromagnetic Exploration by Sampling Delay

Abstract:

Because of the effcetion of primary field. if select the sampling delay blindly, it will cause distortion of explanation of transient electromagnetic exploration. We analysis of the scope of influence of primary field at first, then study on the effect of different delays for detection:the small delay causes the early false anomaly. The full time apparent resistivity is less than the theoretical apparent resistivity. The depth of investigation gets small. On the contrary, the long time delay causes the loss of the superficial ground information. The full time apparent resistivity is more than the theoretical apparent resistivity. So it can reduce the false anomaly caused by the primary field decreases only when the acquisition of the inflection point delay is adopted. Then the computing apparent resistivity is close to the theoretical value and the apparent depth of investigation increases.

• Periodical: Advanced Materials Research (Volume 868)
• Pages: 154-158
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.868.154
• Online since: December 2013
• Authors: Jin Song
• Keywords: Apparent Depth, Apparent Resistivity, Sampling Delay, Transient Electromagnetic

References

[1] Usama MASSOUD,A.M. ABBAS, etc. Mapping of subsoil water level and its impacts on Hawara archeological site by transient and multi-frequency electromagnetic survey[J]. Chinese journal of geophysics, 2010, 53(3): 638~645(In chinese).

[2] Xue Guo-qiang, Li Xiu. The technology of TEM tunnel prediction imaging[J]. Chinese journal of geophysics, 2008, 51(3): 894~900(In chinese).

[3] Research on full-space apparent resistivity interpretation technique in mine transient electromagnetic method[J]. Chinese journal of geophysics, 2010, 53(3): 651~656(In chinese).

[4] Yan shu, Shi Xian-xin, etc. Issues on probing depth of hydrogeological electricalmagnetic method for exploration of north china coal field[J]. Coal science and technology, 2006, 34(12): 5~8(In chinese).

[5] Niu zhi lian. Time domain electromagnetic method[M]. Chang Sha: Central South University Press, 2007(In chinese).

[6] Jiang Bangyuan. Practical near-field magnetic source transient electromagnetic prospecting[M]. Bei Jing: Geological Publishing House, 1998(In chinese).

[7] Ji Yanju, Lin Jun, Wang zhong, etc. Analysis of distortion in all-time transient electromagnetic field based on inducing of ramp switch-off current for shallow survey[J]. Chinese journal of radio science, 2007, 22(2): 315~320(In chinese).

[8] Yu Shengbao, Wang Zhong, Ji Yanju, etc. Time domain transient electromagnetic shallow prospecting[J]. Chinese journal of radio science, 2006, 21(2): 284~287(In chinese).

[9] Ji Yanju. Lin Jun, Yu Shengbao, etc. A study on solution of transient electromagnetic response during transmitting current turn-off in the ATTEM system[J]. Chinese journal of geophysics, 2006, 49(6): 1884~1890(In chinese).

DOI: 10.1002/cjg2.1000

[10] Xu Yang-cheng, Lin Jun, etc. Calculation of full-waveform airborn electromagnetic response with three-dimension finite-difference solution in time-domain [J]. Chinese journal of geophysics, 2012, 55(6): 2105~2114(In chinese).