By using artificial field sources to excite underground rocks, the potential difference generated during the flow of current is received, and the primary field potential formed by different power supply frequencies is received. Due to the different propagation depths of fields at different frequencies in the formation, the reflected depth also forms a mathematical relationship with frequency. Rocks with different electrical conductivity generate different potentials and magnetic fields during the flow of current. The CSAMT method is an electromagnetic exploration method that uses the differences in electrical conductivity of different rocks to observe changes in the primary field potential and magnetic field intensity.
CSAMT uses controllable artificial field sources. Measure the electromagnetic field component transmitted from an electric dipole source to the ground, with a distance of 1-2km between the two electrode power sources. The measurement is conducted in the range of 5-10k

Electrical exploration is an important branch of geophysics, which is an applied science in the fields of electrical engineering, electromagnetics, electronics, and electrochemistry to solve geological prospecting, engineering geology, and environmental geology.
Electrical/electromagnetic exploration technology can be divided into natural field method (AMT) and artificial field method based on the nature of the field. If classified by category, it can also be divided into time domain method and frequency domain method. Electromagnetic exploration technology includes methods such as natural electric field method (SP) and resistivity method（ ρ S; CR, Induced Polarization Method (FDIP; SIP) Charging Method, Magnetotelluric Sounding Method (MT), Controlled Source Audio Magnetotelluric Sounding Method (CSAMT), Transient Electromagnetic Sounding Method (ATEM; TEM), etc.
According to the properties of the field source, it can be divided into direct current method, alternating current me