For discussion: Posts have been made on various boards to the effect that the elevation pattern of a vertical monopole requires reflections from the ground plane some 10 to 100 wavelengths downrange from the monopole before that pattern takes its final shape. Below is a NEC4.2 analysis of the elevation pattern of a vertical monopole, for the conditions and with the observations included in that graphic. The vertical plane (far-field) pattern in that graphic is fully formed at a horizontal distance of less than 10 wavelengths, with its peak gain at 35° elevation. The reduced low-angle radiation seen there is the result of excluding the surface wave in the analysis. The surface wave analysis (left side of graphic) for the same horizontal distance shows that the maximum radiated field from this system lies in the horizontal plane, not at 35° elevation. Low-angle fields shown in the surface wave plot down to about 5° elevation (87.5 meters on the left-hand vertical scale) can propagate at a decay rate of 1/r, which under the right conditions can reach to and reflect from the ionosphere, returning to Earth as skywaves. Note that gain shown for a 5° elevation angle in the space-wave plot are much lower than in the surface-wave plot. Theory shows that elevation patterns radiated (launched) by all base-driven, vertical monopoles of 5/8-wavelength height and less have maximum relative field [E/E(max)] in the horizontal plane for distances of about 1/2 to several wavelengths from the base of the monopole — regardless of the conductivity of the ground plane they are driven against.