The Development Of Transient Electromagnetic Method Receiver Based On Sampling And Integral Technology

Time Domain electromagnetic Method, or which called Transient Electromagnetic methods (TEM), are some kind of electrical discrepancy based on target. It utilizes re-line untouched to ground or re-line touched to ground to transmit once pulse magnetic field toward the underground. In the period of the first field's intermission, measures the induced electromagnetic field (the second field) changed with time which is created by underground substance. So it can measure the position of underground inhomogeneous substance and estimate its scale and electricity capability. This method can be applied in mineral resources exploration. But in working circumstance exiting strong radiation noise, the detecting depth markedly reduced. So we bring forward to make strong field source TEM instrument system to increase the detecting depth. The strong field source TEM instrument system uses two key technologies( large power switch and sample integral) to suppress noise, improve incept signal-to-noise ratio and increase the detecting depth.The strong field source TEM system suppresses noise by means of increasing eradiate field, while to increase eradiate field is hard, and it will bring boundary phenomenon. The sensitivity of the instrument increase with the eradiate electric current, but the bigger the electric current is, the poorer the improvement of the sensitivity is. So it is necessary to search for other methods to enhance the detection depth. The main performance index of transient electromagnetic receiver is the Signal-to-Noise and the receiving sensitivity. Enhances the TEM receiver Signal-to-Noise and the receiving sensitivity, may enhance the detection depth of the instrument with the same eradiate field. The initially signal received in transient electromagnetic secondary field decreases quickly and the dynamic range is big (decreases...