SEGJ Technical Conference


Consideration of precision about a numerical analysis for 3-D conductivity structure by loop-loop electromagnetic induction exploration method


Abstract
The loop-loop electromagnetic exploration method with transmitter and receiver coil s is conveniently used for reconnaissance survey. If we adopt the several kinds of coil spacing and coil setting, sub-surface conductivity structure can be estimated. Now we can utilize one of presentation theorems for 3-D conductivity structure already reported in previous papers by Mendez-Delgado et al.(1999). Their theoretical equation representing apparent conductivity includes a kind of elliptic integrals. Hence we cannot but exert a numerical integral. The results of our first trial of model calculation just the same as previous paper are found to be different from those. Unfortunately we are difficult to find the detailed numerical calculation method in the previous papers. Here we use the simple numerical integral and in addition, 3-D Romberg integral is examined for the calculation of the apparent conductivity. We can calculate the numerical integral with any precision using Romberg integral.