Definition and Improved Algorithm of All-Time TEM Apparent Resistivity

An improved TEM all-time apparent resistivity is proposed. Firstly, we give its definition. Its definition at time t(i) is the comprehensive resistivity of the zone from Depth(i - 1) to infinity, where, Depth(i - 1) is the maximum TEM field diffusion distance at time t(i - 1). Then, we give its algorithm based on the binary search algorithm. Finally, a half-space model and a whole-space model are constructed to test the proposed method. The traditional all-time apparent resistivity and the improved all-time apparent resistivity are calculated respectively by using the models built above. The results show that compared with traditional method, the improved all-time apparent resistivity is more fit to the theatrical model, and have higher precision and resolution.