Radiophysics, 1962 to 1990 Iain Reid Bronwyn Dolman Space and - - PowerPoint PPT Presentation
Radiophysics, 1962 to 1990 Iain Reid Bronwyn Dolman Space and Atmospheric Physics Group Location of Buckland Park and St Kilda Field Stations Buckland Park St Kilda Adelaide The St. Kilda site is about 22 km north of Adelaide and about 3 km
The St. Kilda site is about 22 km north of Adelaide and about 3 km from the coast. It was
two to Bragg in the latter period)
When he arrived in 1948, “The ample buildings housed uneven resources, with Engineering well equipped and Physics a junk- shop”, If the Gown Fits, 1960
“Huxley found …. a department starved as a result of the war of both resources and opportunities to appoint new personnel”, but “…he had the advantage of being able to expand his department rapidly as a consequence of swelling student numbers”, and “…support from an enthusiastic and energetic Vice- chancellor….These years also coincided with the introduction of Ph.D. courses throughout Australia”,
Compton, Historical Records of Australian Science, Volume 8, Number 4.
Cambridge (B.A. 1942; Ph.D. 1952; DSc). Junior Scientific Officer, TRE, 1942 to 1946. Radio Research Group, Cavendish Laboratory, 1946 to 1961 University of Adelaide, 1962 to 1988 Adelaide (BSc(Hons), 1949; Ph.D. 1955). University of Adelaide, 1950 to 1980’s
development in Meteor physics
effectively became a Radiophysics research group under Graham and Basil, encompassing a broad range of activities.
Atmospheric Physics name was adopted
The group is currently classified 80% Space and 20%
Atmospheric for the ERA, and the group name is now Space and Atmospheric Physics
Upper Atmosphere Group 1962 Back row : R. Roper, J. Welsby, C. Nilsson,
Murray, Miss J. Allister, Miss M. Chapman, Dr. G. Elford
1950 Basis of the Adelaide Meteor Wind System constructed December 1951 The first photographic recordings of meteor echoes showing 'Doppler beats' obtained during the Geminid shower. June 1952 Full system operation measurement of atmospheric motion within the height range 75-105 km, by observing the drift of meteor trails; photographic recording, manual analysis March 1955 System operation ceases December 1956 Mawson Station meteor radiant system established, continues to operate intermittently until 1959 1958 St Kilda field site established 1969-72 Buckland Park MF meteor studies Mid-1970s Meteor work at St Kilda ceases Early-1990s Meteor work resumes on the BP ST VHF radar Late 1990s Meteor radar work ‘re-born’ with advent of small pulsed VHF radar systems
Meteor echo recorded in December 1952. The ‘spikes’ on the upper two Doppler beat signals delineate a phantom record displaced in phase by 90º before or after the main traces dependant on the sign of the Doppler signal. The centre pairs of traces determine the direction of arrival of the sky wave. The range is determined from a display at the bottom of the record. The range markers are at 10 mile intervals with the uppermost dotted line set at 10 miles.
(Table modified after Elford, 1994, 2011)
from 1963 until 1980. Karel Bartusek, David Gambling and Stuart Young completed PhD theses in this area.
Antarctic Research restarted lidar work in the late 1980’s, and measurements were made at BP between March 1992 and May 1993 by Stephen Argall.
at Davis Station in the Antarctic, and a new system is under development at BP (Bottom right)
Graham Elford and Basil Briggs with a model the large MF/HF antenna array
D-region partial reflection echo from a single receiver displayed on a CRO Snapshot in time of the amplitude of the backscatter diffraction pattern at the ground. The ground diffraction pattern is the Fourier Transform of the angular polar diagram of the backscattered radio signal
(After Briggs, 1984)
(After MacKinnon, 2001) Correlation analysis (After Briggs, 1984)
Snapshot of the intensity of the electric field strength on the ground formed by the backscattered radio wave
Correlation analysis (After Briggs, 1984) This snapshot is part of a movie of the changing intensity of the ground diffraction pattern produced by the backscattered radio wave on the ground. It was produced by separately driving 89 light bulbs by 89 receivers connected to 89 antennas within the array. A diffusor of ground glass was placed between the light bulbs and the camera.
Snapshot of ground diffraction pattern from the F- region (left) and its focussed image (right) Snapshot of the focussed image of the ground diffraction pattern from the E-region The photograph on the left shows Nigel Holmes (left) and Basil Briggs (right) in front of the ultrasonic image forming system. The schematic diagram on the right shows the principle of operation.
Canterbury, (BSc(Hons), 1964; Ph.D. 1967). Senior Teaching Fellow, 1970 to 1973 University of Adelaide, 1973 to 2011
and gravity wave studies
momentum fluxes in the troposphere and stratosphere
balloons
Adelaide, (BSc(Hons), 1976; Ph.D. 1982). University of Adelaide, late 1980s to early 1990s
Radar beam 1 Radar beam 2
2 sin 2 ) , ( ) , ( ) (
2 2 2 1
R v R v z w u
Summer Winter
Adelaide, (BSc(Hons), 1979; PhD, 1985; DSc, 2008). University of Adelaide, 1988 to present
electron densities and gravity wave studies
Lower Thermosphere region