Hardware and Software for the Llanherne Low Frequency Sky Surveys

Since 1971, the Llanherne low frequency radio telescope (Ellis 1972) has been used to conduct surveys of the sky at several decametric wavelengths. Prior to 1974, only pen recordings on paper chart for one declination at each of the wavelengths were obtained each night and all the work to produce the final sky maps was to have been done by hand. However in 1974, a general purpose digital minicomputer (a Digital Equipment Corporation PDP 8/E) has considerably increased the research capabilities of the telescope. In the continuum sky surveys profiles at several different declinations are now obtained each night. In addition all the information gathered in an observing session is written onto magnetic tape which is later analysed on the University of Tasmania’s computer (an Elliot-503) thus providing the possibility of removing much of the tedious manual work in preparing the final sky maps. This paper describes the system developed by the author which is used by Cane (1975) to obtain the profiles from which the sky maps are being compiled.