Development and applications of geometric-sounding electromagnetic (EM) systems
Richard S. Taylor · 1999
Howell’s (ibid.) instrument incorporated a perpendicular system but, due in part to design tolerances, this system became much less popular than the horizontal co-planar system, in which the windings of the transmitter and receiver are horizontal and co-planar. Figure 2 is a schematic profile of the horizontal co-planar system; its cumulative response (after McNeill (ibid.)), in the terms used previously, is: