Focus on the history of Australian radio astronomy
Introduction
Ever since their pioneering efforts in radar technology during WWII, Australians have been at the forefront of international radio astronomy (Sullivan 1988). The earliest observations of importance were conducted by staff from the CSIRO's Division of Radiophysics at the Dover Heights field station in Sydney (see papers in Goddard and Haynes 1994), which was soon joined by other major field stations at Potts Hill, Dapto and Fleurs. During the 1950s and 60s other smaller and often temporary field stations were established at such scattered places as Badgery's Creek, Georges Heights, Hornsby Valley, Murraybank and Penrith.
Christiansen (1984: 113-115) has painted a poignant picture of these field stations:
"The field work had a pioneering appearance. Each morning people set off in open trucks to the field stations where their equipment, mainly salvaged and modified from radar installations, had been installed in ex-army and navy huts. At the field stations the atmosphere was completely informal and egalitarian, with dirty work shared by all.... there was no place for observers who were incapable of repairing and maintaining the equipment."
This idyllic existence came to an abrupt end with the construction of the Parkes Radio Telescope. The 64-m antenna marked the start of an era of `big science' in Australian radio astronomy (Robertson 1992), and heralded the closure of the scattered field stations.
Historians of science are very fortunate that for much of its existence the Radiophysics/ATNF infrastructure allowed the employment of professional photographers, and through the efforts of the late Ken Nash, John Masterson and their assistants an up-to-date visual record of personnel, special events, new radio telescopes and auxiliary equipment was maintained. This unique heritage resource is currently under the stewardship of the ATNF in Sydney.
The ATNF historic photographic archive
The Historic Photographic Archive dates from 1939 and comprises ~50,000 individual negatives or slides, and associated prints. The negatives are in envelopes and stored in metal card cabinets, while the slides are in two filing cabinets and two large purpose-built "slide cabinets" with horizontal shelves and built-in light boxes. The prints, for the most part, are housed in filing cabinets and in numbered "photo books".
Documentation on the images is preserved in a Filemaker Pro database, and a start has been made transferring the most interesting and historically-significant images onto a digital image-library database.
Recently, the collection was relocated to a new purpose-built room at the ATNF's headquarters, and temperature and relative humidity are maintained at acceptance levels with the aid of a dedicated air conditioning unit and a dehumidifier.
Even a cursory survey of the negative cabinets and print files reveals a veritable treasure-trove of riches. In addition to images of many the key figures in Australian radio astronomy, there are photographic records of key events in the history of Australian radio astronomy - such as the official openings of the Parkes Radio Telescope, the Culgoora Radioheliograph and the Australia Telescope.
The collection also contains panoramic views of many of the Division's field stations, and photographs of most of the radio telescopes made at one time or another by or for Radiophysics and later the ATNF.
For example, from Dover Heights we have the 2, 4, 9 and 12-Yagi arrays, the 4.9-m parabola atop the WWII blockhouse and the famous 21.9-m `hole-in-the-ground' antenna that was later extended to 24.4 m (Figure 2). Australia's mini-Aricebo was used to survey the sky at 160 MHz and to search for the deuterium line (Bolton 1982).
Dapto is well-represented by views of the field station and those distinctive rhombic aerials (Figure 3) used for spectrographic solar studies, and to this group we should perhaps add the original prototype antenna which was located at Penrith.
The Potts Hill field station contributes a pot-pourri of instruments: Yagi arrays and stand-alone parabolic antennas used for solar work, the grating interferometer situated beside one of the reservoirs, the rectangular parabolic antenna and the 11-m dish used for the early H-line work, and the prototype `Mills Cross' (Figure 4).
The collection also contain photographs of the broadside arrays used for the 3-element interferometer which were situated at the short-lived Badgery's Creek site, and of the 6.5-m dish that was erected at the Murraybank field station for dedicated H-line work.
For its part, Fleurs boasts a series of excellent aerial views of the site, plus details of the Chris Cross, Mills Cross and Shain Cross (see Figure 5). Also represented is the 18.3-m antenna, used in conjunction with the E-W arm of the Chris Cross before its transfer to Parkes, and some of the temporary antennas used by Slee et al. for long baseline interferometry. There are also images of the barley sugar arrays used at some of the remote sites, including the one at Llandilo that I clearly remember visiting with Sheuer back in the 1960s while serving as his technical assistant.
Understandably, the Parkes segment of the collection contains a large number of colour and black and white images documenting the design, construction and research programs associated with the 64-m antenna, and its 18.3-m satellite parabola (eg see Figure 6).
Culgoora boasts a 35-year record of achievement, beginning with the site preparation and construction of the Radioheliograph and extending to the establishment and subsequent development of the Australia Telescope Compact Array. Forming a natural extension of this latter sequence are images of the Mopra dish near Coonabarabran.
Finally, the Division's current Marsfield site is represented as the home of the 4-m precision-built radio telescope that was opened in 1976 and used for molecular line studies of the Galaxy at millimeter wavelengths.
Although some of the images in the collection have already appeared in print (e.g. see Deane 1985; Sullivan 1984), the ATNF Historic Photographic Archive remains an invaluable resource for those researching the history of Australian astronomy or international radio astronomy. The Archive also has enormous educational potential - particularly at the secondary school level - and given the heightened public interest in both astronomy and Australian history it could also serve as the basis of a succession of popular travelling exhibitions. These are but some of the ways in which this important collection can be used to promote science and technology and allow the Australian public to share in the achievements of some of our most famous scientific sons and daughters.
References
Bolton, J., 1982, Proc.Astr.Soc.Austr., 4, 349-358.
Christiansen, W.N., 1984, in Sullivan, 112-131.
Deane, J., 1985 A Picture History of CSIRO Radiophysics, Division of Radiophysics, Sydney.
Goddard, D.E., & Haynes, R.F. (eds.), 1994 Pioneering a new astronomy, Austr.J.Phys., 47(5).
Robertson, P., 1992 Beyond Southern Skies. Radio Astronomy and the Parkes Telescope, CUP, Cambridge.
Sullivan, W.T., 1984 The Early Years of Radio Astronomy, CUP, Cambridge.
Sullivan, W.T., 1988 Early years of Australian radio astronomy. In Home, R. (ed.). Science in the Making, CUP, Cambridge, 308-344.
Wayne Orchiston
(Wayne.Orchiston@csiro.au)
Figure 1: The opening of the Australia Telescope on 2 September 1988.
Figure 2: The Dover Heights `hole-in-the-ground' antenna.
Figure 3: The rhombic aerials at Dapto.
Figure 4: A view of Potts Hill showing the prototype Mills Cross and in the background two of the antennas used for H-line work.
Figure 5: A view at Fleurs showing the central section of the Mills Cross and in the background part of the Chris Cross.
Figure 6: The 64-m and 18.3-m radio telescopes at Parkes.