Characteristics Of Multiple Source And Study On Tensor Measurement In CSAMT

Controlled Source Audio frequency Magnetotellurics, referred CSAMT method, is a frequency-domain electromagnetic sounding method. The principle is the use of artificial source emits an alternating current alternating electromagnetic field, by observing the electromagnetic response to calculate the apparent resistivity and impedance response. The ways of measurement by Frequency domain controlled source magnetotelluric method follows the AMT, electrical source mainly used to be artificial source, because the electrical source is easy to realize, have a bigger field distribution and greater depths in CSAMT method, used for coal exploration, geothermal, oil, gas and solid minerals deep prospecting, etc. Traditional measurement methods are based on a single source measurement, in recent years, increased multi-source tensor CSAMT measure emphasis, this paper preliminary research on multi-source features and tensor measurement.Firstly, based on the Maxwell equations deduced the horizontal electric dipole source in the surface layer of the earth’s electromagnetic response. Realized by programming of one-dimensional CSAMT forward, then we can calculate the field distribution at the surface. At the same time, Based on the principle of vector superposition to obtain a distribution of the superposition of the two electric dipole field source, in line with the principle of vector superposition. Through the symmetry of electromagnetic field realized tensor CSAMT one dimensional forward, analysis the characteristic of elements of tensor impedance and magnetic transfer functions in different types of geoelectric section.Next, through to analysis of the tensor CSAMT measurements, we research the exploration depth, the lowest operating frequency, the distance of receiving and transmitting and other parameters of tensor CSAMT method. Particularly for the observation area of different transmitter sources t, mainly analyzes and summarizes the experimental study on the current domestic and international, L-type and rotary dipole source emitting device suitable observation area, after the actual measurements of the tensor CSAMT have some reference values.Based on the characteristics of tensor CSAMT data, this paper have preliminary study the general steps of data processing of tensor CSAMT, Including spectrum information extraction, strike impedance tensor lements and spindle orientation. Then do inversion of apparent resistivity obtained by the spindle direction.Finally, we use CSAMT regularization method to achieve a one-dimensional inversion of full information, the inversion results can better reflect the geoelectric section type.