Research on Application of all Time Apparent Resistivity Translation Algorithm for Large Fixed Loop TEM

In order to calculate the all-time apparent resistivity for large fixed loop more quickly, the transient electromagnetic field analytic expression for lager fixed loop in homogeneous half space is analyzed in this paper. The facts that the curve has a characteristic of translational expansion and contraction with the conductivity, the test point coordinates and observation time are discovered. A new method using translation algorithm to calculate all-time apparent resistivity is proposed for the large fixed loop. A new calculation equation of all-time apparent resistivity for large fixed loop is derived which shows that the method is feasible and effective.