Curtin University senior professor Peter Teunissen has seen the field of satellite technology expand at a phenomenal rate over the past few decades. From a distance of thousands of kilometres, satellites can now help detect ore deposits on Earth, determine the moisture content of soil for better crop planting, provide instant navigation assistance for walkers and motorists, accurately predict weather patterns and ensure that no-one with a satellite-connected device will ever be truly lost again. A car can be tracked across a desert, a military expansion documented and a glacier’s retreat observed minute by minute and in intimate detail.
Today, dependence on global navigation satellite systems (GNSS) has penetrated all levels of society, Teunissen says. “The timing systems we are using for computers, the synchronisation of timing – that’s all linked to GNSS,” he says. “All those satellites are equipped with the most accurate atomic clocks. We are all now dependent on those GNSS systems.”
Awarded an Australian Research Council Federation Fellowship, the precursor of the current ARC Laureate Fellowship, Teunissen moved to Australia more than a decade ago. He has been associated with Curtin University since 2009 and he is now an award-winning and internationally-recognised expert in the field of satellite technology, specialising in interferometric GNSS, the use of satellite signals for the high precision measurement of the parameters of water and land masses.
The new frontier of miniaturised satellites has also caught Teunissen’s attention. Called cubesats – and often not much larger than a loaf of bread – the mini-satellites are within the economic reach of universities and corporations.
“A lot of research at the moment is focussed on the next generation of GNSS satellites; one segment is looking at lower-cost satellites, such as cubesats,” he says. “The cubesats really are the future for increasing the number of satellites and constellations because even students, of course with proper supervision, are able to design satellites and then they can be launched with a much lower budget.”
Teunissen has been fascinated by the potential of satellite technology from the field’s earliest days. As a professor of geodesy, classically the study of the earth’s shape and surface, in the early 1990s he was invited to choose his own specialisation at the Delft University of Technology in the Netherlands.
He looked to the emerging field of satellite technology and discovered that his homeland had no GPS know-how, no GPS infrastructure and no GPS equipment. He used generous grant funding the Netherlands’ Royal Academy of Sciences to buy the nation’s first GPS receiver for US$300,000. As a demonstration of the rocketing speed of the field’s development, he says that nowadays such a GPS receiver might cost US$100.
Developed by the US military, GPS was the first of the global navigation satellite groupings, and now all but one of the systems, four global and two regional, work with potentially difficult hybrids of military and civilian control, Teunissen says.
The US military, for instance, retains an interest in the GPS system, Russian military interests prevail with the GLONASS Russian GNSS system, and China exerts control over the nation’s BeiDou system. “Of the global systems, only the European system, Galileo, which became operational last year, is entirely a civilian operation,” Teunissen says.
Each system has an average of 30 satellites orbiting at an altitude of about 20,000 kms, and between them they cover every square centimetre of the earth’s surface. The civilian side of GNSS is “broad, open, transparent; working with and improving systems”, Teunissen adds, but military forces can have different priorities. During the Iraq war, for instance, the US military ensured the GPS covering Iraq was limited to US military use.
“I see some potential difficulties ahead, yes,” Teunissen says. “The control of the GPS system can easily be taken back by the military.”