Defocusing of radio rays by the troposphere

Abstract

When radio rays pass th rough t he atmosphere, they are defoc Llsed due to its presence.This effect is measu red by the divergence coefficient a nd general formulas are derived for D1, the dive rge nce coefficient of t he direct ray, and D" the divergence coefficient of the reflected ray-assuming a smooth spherical earth . As examples, D I a nd Dz are shown for some typical cases with an "exponential" atmosphere (troposphere).

Focusing of Waves in Ducts

“…Focusing of waves in naturally occurring ducts (regions of space with appropriate distribution of refractive index) is of considerable importance in tropospheric communications [Bean, 1954;Barsis and Johnson, 1962;Wilkerson, 1962], ionospheric propagation [Carrara et al, 1970], and sound propagation in sea water [e.g., Gordon, 1965, 1970] and atmosphere. The work on tropospheric propagation is essentially qualitative in nature, and the investigations on ionospheric propagation normally resort to numerical computations.…”