On: “IP and Resistivity Type Curves for Three‐dimensional Bodies” by K. Dieter, N. R. Paterson, and F. S. Grant (GEOPHYSICS, Vol. 34, no. 4, August, 1969, p.615–632).

Abstract

All boundary conditions of the problem discussed by Dieter et al cannot be satisfied by the solution given in equations (8) and (9). It is not adequate to consider just one image in the manner illustrated by Figure 2. There will be a series of higher order images: [Formula: see text] and [Formula: see text] will be reflected on S giving the next image. This image in turn will be reflected on [Formula: see text]; and so on. Equations (8) and (9), therefore, represent an approximation—not a very good one—and will hold approximately only under very restricted conditions (see, for instance, “Interpretation Theory in Applied Geophysics” by F. S. Grant & G. F. West, p. 425, McGraw‐Hill Book Company, N. Y.). They do not constitute “a perfectly suitable form” for the potential due to a closed conducting body in a half‐space.