- Volume 20 Issue 1
An analysis is made for the relative effectiveness in detecting a subsurface thin layer by four electromagnetic depth sounding systems; horizontal coplanar loops, perpendicular loops, vertical coplanar loops and vertical coaxial loops. The moduli and phases of mutual coupling ratios over a three-layered earth for the four systems are evaluated rapidly by the related convolution technique. Root mean square differences between the responses from the three-layered and the homogeneous earths are used to compare the relative effectiveness of the systems quantitatively. Comparing the all systems, it is found that the perpendicular loop system appears to be the most superior to the other systems.