Prof. Stuart Anderson
Space and Atmospheric Physics Group, School of Physical Sciences, University of Adelaide
Observing the geophysical environment and its dynamics with decametric radar
Monday, May 9, 2016, 3:00pm to 4:00pm | Room 3-434
Radars operating at decametric wavelengths - popularly known as 'over-the-horizon' radars because of their ability to exploit non-line-of-sight propagation mechanisms – possess unique capabilities for observing the environment on a synoptic scale and measuring a variety of geophysical parameters. These remote sensing applications have been the subject of continuing research since the 1950's, with over 500 radars presently operating in the HF band, 3 – 30 MHz. The majority of these exploit the surface wave mode of radiowave propagation, some use the skywave mode, and a few employ line-of-sight or more exotic mechanisms.
By far the best known decametric radar observables are integral and bulk properties of the upper ocean, such as significant waveheight, dominant wave period and direction, and surface current velocity, but the ocean is not the only domain whose state variables and dynamics imprint themselves on the radar signals in ways which offer the prospect of information retrieval. Decametric radar signatures of conditions and phenomena in the lithosphere, the cryosphere, the atmosphere, the ionosphere, the magnetosphere and the heliosphere have all been subjects of inquiry by the radar community and, in many cases, these studies have yielded significant insights and sometimes unique windows onto the associated physics. Recently it has been demonstrated that observability can be extended to include quite subtle aspects of dynamical processes characterised by nonlinearity, non-adiabaticity, non-Gaussianity and other complex behaviour.
In this talk I shall describe the remote sensing abilities of decametric radar with reference to the observation process and its limitations, the electrodynamics of the interaction mechanisms, the intrinsically nonlinear and multiscale nature of the geophysical environment, the ill-posedness of the inversion problem, and the symbiosis of this sensing modality with other technologies.
Stuart J. Anderson received the B.Sc. and Ph.D. degrees in physics from the University of Western Australia. In 1974, he was invited to join the team being assembled in the Australian Defence Science and Technology Organization to develop the Jindalee over-the-horizon radar system where he assumed responsibility for ocean surveillance and remote sensing. In the 1980's he spent a year at the Naval Research Laboratory in Washington DC, working as a visiting scientist on the US Navy Relocatable OTH Radar (ROTHR). Stuart holds adjunct professor appointments at several Australian universities, including his principal appointment at the University of Adelaide, having retired from DSTO in 2014. In addition, Stuart is a professor at the Université Rennes I, France, which, in 2005, awarded him an honorary doctorate for his contributions to radar science. He was the recipient of the 1992 Australian Minister of Defence Science Award for Research Achievement. He has published well over 300 journal papers, conference papers, book chapters, and reports in these fields and is the principal author of the chapter on OTH radar in the authoritative Radar Handbook.