Kenneth George Budden. 23 June 1915 — 4 September 2005

After the discovery of the ionosphere in 1924 by E. V. (later Sir Edward) Appleton (FRS 1927), there was extensive experimental research into its properties with the use of radio reflection techniques. This generated a need for theoretical investigation of the propagation of electromagnetic waves in ionized gases, nowadays known as plasmas. This led eventually to a large body of work known as magnetoionic theory. A start was made by Appleton himself, but much was left for later research. The systematic exploration of this subject was pursued in the decades after World War II, and Kenneth Budden was a leading contributor to it for most of his research career. He also expounded it in a large textbook, which he rewrote two decades later. The arrival of electronic computers in the early 1950s (however primitive they may appear with hindsight) opened new prospects for many branches of science. Kenneth Budden was one of the pioneers in that activity.

3. Radio reflections from meteor trails

Intensive development of the radar method of investigating meteors and connected phenomena in the Earth's atmosphere required studying interaction of radio waves with ionized meteor trails. Approximate solutions of the problem of radio reflection by ionized meteor trails have been obtained in a number of papers (Feinstein, 1950; Herlofson, 1951; Kaiser and Closs, 1952; Manning, 1953, 1963; Eshleman, 1955; Brysk, 1958, 1959).