Paul Wild stands tall among the founding fathers of modern radio astronomy. His early work became the foundation for all future research on solar radio bursts. He established the theory and identified the different types of radio bursts. He developed new types of instrument including the dynamic spectrograph and a radioheliograph to make two-dimensional movie images. His early interest in the radio spectrum of hydrogen led to analysis of the hyperfine structure of hydrogen emission and a publication that became a classic paper in the field. Recognition that the 21 cm hydrogen line could be used to measure the Zeeman effect and through that magnetic fields in astronomical sources was another key contribution to modern astronomy. He became Chief of the CSIRO Division of Radiophysics and developed and demonstrated an outstanding microwave landing system for aviation. As Chairman of CSIRO he led the organization through a major restructuring and adapted CSIRO to bring it closer to industry while maintaining a high standard of excellence and originality. Throughout his career, Paul Wild provided great leadership at all levels of science in Australia.
W. N. (?Chris') Christiansen was an innovative and influential radio astronomy pioneer. The hallmarks of his long and distinguished career in science and engineering, spanning almost five decades, were his inventiveness and his commitment to, and success with, large-scale projects. These projects were the outcome of his innovative skill as physicist and engineer. Paralleling this was his equal commitment to forging strong international links and friendships, leading to his election as Vice-President of the International Astronomical Union for the years 1964 to 1970, as President of the International Union of Radio Science, URSI, from 1978 to 1981, and subsequently as Honorary Life President in 1984, and as Foreign Secretary of the Australian Academy of Science from 1981 to 1985. Major subsequent developments in radio astronomy and wireless communications on the global scene stand as a legacy to Chris's approach to his work and to the development of those who worked with him.
Apparatus to measure the correlation between two wideband (10-100 MHz) noise signals has been developed for the stellar intensity interferometer at the Narrabri observatory. This instrument is used to measure the angular diameters of stars in the range 0 • 01 -0• 000\" of arc, with an accuracy within about 5 % To achieve this precision with the low signal/noise ratio of an intensity interferometer, it is necessary to integrate and average the data for periods up to lOOh, which may involve observations spread over several weeks. The paper describes the novel techniques which have been used to obtain the necessary efficiency and stability in the electronic correlator.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.