Although the free space attenuation is inverse square, interference effects can increase power attenuation for radio waves in the far field limit. If there is r

Although the free space attenuation is inverse square, interference effects can increase power attenuation for radio waves in the far field limit. If there is reflection off the ground, the power attenuation is closer to inverse quartic in the far field. https://en.m.wikipedia.org/wiki/Two-ray_ground-reflection_model https://en.m.wikipedia.org/wiki/Two-ray_ground-reflection_mo...