Bulletin

Issue: April 2005

News

La Trobe spectrometer for Antarctic base

Some time in the southern summer of 2006/7, a state-of-the–art imaging spectrometer—designed and manufactured at La Trobe University—will be installed at Australia’s Mawson Antarctic base.

From that moment there will be a vastly improved flow of up-to-the-minute data about the winds and temperatures in Earth’s upper atmosphere and ionosphere—more than 100 km above the planet’s surface.

‘This enhanced measurement resolution will lead to a signi-ficant contribution to understanding space weather impacts on communications, navigation, surveillance capability, and the operation of low altitude satellites,’ says the designer of the spectrometer, space physicist, Dr Mark Conde.

Dr Conde, a senior lecturer in La Trobe’s Department of Physics, and Professor Peter Dyson, the Department’s Head, have received an ARC Discovery grant of $335,000 over three years to develop and manufacture the imaging spectrometer.

The new device will be used to observe the very top layers of Earth’s atmosphere. Obtaining a close-up picture of wind patterns at this altitude was previously in the space weatherman’s “too hard basket.” It was too high for observations in-situ by aircraft or balloons, and too low for orbiting satellites.

Dr Conde’s new spectrometer is a major improvement on the first generation of such instruments, which have operated since the 1970s and are in some cases still being used.

These older instruments are used to measure wind and tempe-rature within a very small patch of sky. Using a fish-eye lens, the new instrument will be used to observe the entire sky simultaneously, thus mapping wind and temperature variations across a circular region approximately 1,000km in diameter.

Wind and temperature disturbances at this scale occur as Earth’s atmosphere is buffeted by eruptions from the Sun. However, they have not been well mapped in the past because the myopic view of the older instruments prevented them from being used to see all the detail that we now know is present.

These disturbances, depending on intensity and location, can interfere with certain kinds of navigation, communication and other equipment – especially at the high latitudes of Antarctica.

‘When we can collect data about them on a much broader scale, we will be in a better position to understand and ultimately to predict their effects,’ Dr Conde said.

Other expected benefits include support for specific Australian programs such as the $1.8 billion Jindalee Operational Radar Network (JORN) with improved real-time specifications of ionospheric conditions in our sector.

The JORN is a sophisticated new radar network designed to monitor air and sea movements across 37,000km of Australia’s coastline and 9 million square kilometres of ocean. It is being used to cast a security shield across Australia’s remote northern approaches without the high cost of maintaining constant maritime and air patrols.

The new imaging spectrometer would also be used to estab-lish Australia’s leadership of a powerful new technique for atmospheric remote sensing and enable leading-edge research and student training in photonics.

When finished in two years’ time, the device will undergo tests both at La Trobe’s observatory at Beveridge and perhaps in Adelaide before being shipped to Mawson.

Mr Theo Davies, a La Trobe University research fellow who will work with Dr Conde and Professor Dyson building the spectrometer, is planning to travel to Mawson to supervise the installation.

The device will be about half a metre wide long, half a metre wide and two metres high—small enough to be transported by a helicopter. It is based on a prototype Dr Conde built while at the University of Fairbanks, Alaska, from where he collaborated with Professor Dyson.

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