Thomas Lydwell Eckersley
Thomas Lydwell Eckersley (1886-1959) of Marconi's Wireless Telegraph Co
1959 Obituary [1]
WE regret to record the death on February 16 of T. L. Eckersley, whose work with Marconi's Wireless Telegraph Company, Ltd., on the propagation of radio waves has been recognised internationally as of fundamental importance in the development of communication and broadcast systems.
Thomas Lydwell Eckersley, a grandson of T. H. Huxley, was born in 1886 and educated at Bedales School. It was during his service in the first world war with the Royal Engineers in Egypt and Salonika that he made his first important experiments on night effect and coastal refraction phenomena, an understanding of both being essential to the use of radio direction finding in navigation.
On joining the research staff of the Marconi company in 1919, he began the work on the resistance of transmitting aerials which, when published in 1922, earned the award of the Duddell Premium of the Institution of Electrical Engineers. Later, he analysed the findings of the research team sent to Australia by the Marconi company to study long-wave propagation and the results were embodied in a classic paper, of which he was a joint author, entitled "Report on Measurements Made on Signal Strength at Great Distances During 1922 and 1923 by an Expedition Sent to Australia." The paper was published in the Journal of the Institution of Electrical Engineers, Volume 63, October, 1925, page 933.
In connection with the Marconi-Franklin beam system, Eckersley turned his attention to the propagation of high-frequency electromagnetic waves, and between 1924 and 1939 directed a research team by which many pioneer ionospheric investigations were conducted. His work on the basis for predicting the performance of high-frequency radio services, published in later I. E. E. paper, was confirmed brilliantly in practice.
Eckersley applied the phase integral method both to the magneto-ionic theory of ionospheric propagation and to the problem of the effect of the earth's resistivity on the diffraction of radio waves round the earth, communicating his work in several papers to the Royal Society, of which he was made a Fellow in March, 1938. These researches were extended to the tropospheric propagation of very high frequencies and are to a great extent the basis of present-day systems of forward scatter transmission.
In 1940 Eckersley joined the staff of the Air Ministry for secret work and in 1942 became Chief Scientific Adviser to the Interservices Ionosphere Bureau, established at the Marconi Research and Development Laboratories at Great Baddow. His contribution to radar techniques were important and his theories were of value in improving the radar detection of submarines when masked by sea scatter.
Eckersley was obliged by ill health to retire from his post as senior research engineer with the Marconi company in 1946 but continued as a consultant to the company. He was awarded a Fellowship of the American Institution of Radio Engineers in the same year; the citation stated, inter alia: "Both his approach to the problem from the standpoint of practical communications and his invention of mathematical tool useful in the computation of radiated fields are achievements of lasting value, acclaimed by the whole radio world and form a monument of which he may be justly proud."
In 1951 he received the Faraday Medal for achievements in radio research, particularly for outstanding contributions to the theory and practice of radio wave propagation.