Surveillance, Detection and Information

Long before Project Jindalee (described later) was designated as such, an in-depth program of research into the nature of the ionosphere was undertaken. Fifty years of civil research had examined closely its general properties, such as the heights of the layers and enabled the prediction of maximum usable frequencies, but no data existed on the coherence properties which would be essential for large area irradiation and detection. In addition, studies had to be made of the problems of near real time processing of large amounts of data and the extraction of weak signals from clutter and noise. This work occupied for some time almost all the resources of the Applied Physics Wing under M. S. Kirkpatrick and the Engineering Wing under E. B. Davis (later to be called respectively the Electronics Research Laboratory and the Advanced Engineering Laboratory of DRCS).

Although the medium was very different, similar research was conducted in topics relevant to undersea surveillance, location and identification. Studies of the propagation of sound in the sea, noise and clutter, signal extraction and processing, radiation systems were undertaken in the Weapons Research and Development Wing (later the Weapons Systems Research Laboratories) under the leadership of J. W. Crompton and H. A. d'Assumpcaõ. The Navy itself and the Royal Australian Naval Research Laboratory (later to be absorbed into DRCS) had conducted extensive studies of the oceans in Australia's neighbourhood, and these data gave the lead to new concepts of frequency allocation and prediction. In the experimental work, new techniques and instruments such as expendable bathythermographs and acoustic arrays were developed.

A mathematical model of the sea properties was intended to include wind, and surface temperature. The oceanographic program included a study of the Australian East Coast eddies, currents in the Tasman Sea, and the Leeuwin current of Western Australia. The mixing and modification of the thermocline due to these perturbations was included in the ocean model. Propagation studies along new lines enhanced the use of the model.

The totality of the signal processing skills acquired during the research found application in many other areas. Electronic warfare had long since been extended from simple message interception to, among other things, radio attack on guided missiles. The WRE skills were applied to studies and simulations of counter-measures and counter-counter-measures. Signal processing studies to such topics as night vision, digital communications and also extended the practical use of lasers for depth sounding, and for air-borne mapping.

Australian Academy of Technological Sciences and Engineering