The measurement and prediction of v.h.f. tropospheric field strengths at distances beyond the horizon

Following a brief historical review of theoretical and practical deductions concerning the characteristics of v.h.f. tropospheric propagation beyond the horizon, an account is given of a series of measurements made since 1948 by the Post Office at receiving sites within the United Kingdom. Particular attention is given to the concept of angular distance and to the effect of path profile on the median levels of field strength, as well as on the range of fading observed. Simple transmission laws deduced from the observed data enable empirical curves of field strength versus distance to be drawn for various percentages of the time.