Highlighting our history: the world's first solar radiospectrograph--Penrith 1948-1949

[Extract] The first radio observations of the Sun made by Lindsay McCready, Ruby Payne-Scott and Joe Pawsey from the CSIR’s Division of Radiophysics were conducted at 200 MHz from October 1945 using wartime radar installations at Collaroy, North Head and Dover Heights (Orchiston et al., 2006). The earliest chart recordings showed two distinct types of sporadic activity referred to as isolated bursts and outbursts which differed in their intensity and duration. A third type of persistent activity, called noise storm bursts, was reported by Cla Allen (1947a), who was observing at the Commonwealth Solar Observatory on Mt Stromlo