The History of Radio Wave Propagation up to the End of World War I

Hertz in the 1880's demonstrated electromagnetic wave propagation predicted by Maxwell from his equations in 1864. Heaviside and Kennelly postulated the ionosphere to explain Marconi's historical transatlantic reception of radio waves in 1901. Austin derived the first formula for radio propagation in 1911 from experimental data in the kilometer wavelength range taken in the daytime. Much theoretical effort was expended on the effect of the electrical properties of the ground but the problem was not resolved until a later date. Watson, however, cleared up the problem of diffraction around a perfectly conducting sphere in 1919. Up to the end of World War I, it was generally believed that radio transmission improved with increase in wavelength so the experimental data is concentrated in this region.