An investment of R22 million by the CSIR in a state-of-the-art X-band antenna has bolstered the capacity of its Satellite Applications Centre to track more earth observation satellites and increase its archive of earth observation data.
Welcoming guests from government, academia and industry at the inauguration event held at the CSIR’s Hartebeesthoek site on 25 March 2009, Dr Sibusiso Sibisi, CSIR president and CEO, noted, “This expansion to our existing antenna farm here at Hartebeesthoek represents our proactive commitment to support the establishment of space-related infrastructure.
“We are now in a position to acquire additional valuable data to support national, regional and global priorities, and can remain a relevant player in the international tracking, telemetry and command field to support space launches. However, our commitment extends beyond these priorities to those related to the formation of our new South African national space agency.”
The keynote speaker at the event, Dr Mosibudi Mangena, minister of science and technology, highlighted the need for “South Africans [to] share the global custodianship of the Earth. We are specifically responsible for the upkeep of a particularly beautiful part of it, and today we are here to celebrate a new tool that will help us carry out our duty more effectively.
“There are many agendas for space, but none is more important to the South African cause than the task of looking after our own country and monitoring its progress. In this endeavour, satellites are key, and the CSIR’s highly successful Satellite Applications Centre is at the forefront of this critical effort.”
In keeping with his responsibilities for advocacy on the Space Affairs Council, Ron Beyers of the Meraka Institute was enthusiastic about opportunities to expose learners to space science in action, “We need to find future and current students with the right attitude to solve real-world problems.”
The capabilities of the X-band antenna will boost the CSIR’s data democracy project as well as government-funded initiatives, such as the Department of Science and Technology-funded South African Earth Observation Strategy, and the delivery of SPOT 5 data to all government stakeholders on a yearly basis.
The CSIR Satellite Applications Centre’s tracking, telemetry and command group supported 50 successful launch support operations over the past three years, 22 of which were performed in the past year. It downloaded 22 terabytes of data over the past year and has been selected by the European Space Agency to host a Galileo earth station. Galileo is a global navigation satellite system that will provide more precise measurements than those available through the global positioning system (GPS).
Facts about the X-band antenna
The antenna was purchased from French company In-SNEC and imported from France, and has been fully operational since January 2009. It can carry 87% of the earth observation download to allow for necessary maintenance on other antennas. The civil engineering and construction was done locally within a period of four weeks. Some 30 tons of concrete form the base of the antenna as a counterbalance to the ‘sail’ effect of the dish when the wind blows.
With a dish diameter is 7,3 m, the antenna’s position was carefully selected in relation to the other antennas on site. Its altitude at 1500 m is higher than some sections of the Magaliesberg mountains to the north. It was installed by a French team working with 10 CSIR staff, led by Pieter Kotzé, a specialist radio frequency engineer.
The antenna can change position at the rate of 3° per second, allowing it to alter its orientation quite rapidly to track a passing satellite. It is fully automated, meaning that it follows previously programmed instructions regarding the timing and spatial location of passing satellites, and moves automatically when needed.
It receives signals from satellites in the frequency range of 8,0-8,5 GHz, with a figure of merit of 32,2 dB/K. This makes it the most sensitive X-band antenna at Hartebeesthoek as it outperforms the 10 m antenna with its 20-year-old technology. Once the earth observation signal is received by the antenna, it is down-converted to a lower frequency in the shelter before being sent by underground cable to the earth observation data centre, where the information is demodulated and stored for further processing.
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