Radio Propagation above 40 MC over Irregular Terrain

Radio transmissions in the vhf and uhf frequency region over land areas always contend with the irregularities of the terrain and the presence thereon of dispersed quantities of trees, buildings, and other man-made structures, or wave propagation incumbrances. The determination of path attenuation is not easily satisfied by simple, curved, or plane earth calculations. However, quantitative wave propagation data are available in varying degrees which take into account conditions experienced by fixed-to-fixed and fixed-to-moving transmissions over irregular terrain. This available statistical wave propagation information on terrain effects vs frequency, antenna height, polarization, and distance is analyzed, expressed by empirical formulas, and presented in the form of nomographs and correction curves amenable for use by the systems engineer.