Shielding GPS Antennas from Space Radiation
Published on: 3rd Jan 2008
Note -- this news article is more than a year old.
In the European Space Agency's (ESA) 'Swarm' mission in 2010, GPS antennas will measure the Earth's magnetic field with extreme accuracy. Factors such as the right position on the satellite are particularly crucial. A new software program jointly developed by Ericsson and others can simulate complex antenna systems, saving time and money.
They are due to swarm out in 2010: The European Space Agency ESA plans to send three miniature satellites into orbit at an altitude of about 450 kilometers above Earth. The task of the 'Swarm' mission is to study the Earth's magnetic field and its changes more thoroughly than ever before. The researchers expect to gain a better understanding of the processes deep inside the Earth and of the global climate.
For 'Swarm' to fulfill its mission properly, it requires high-precision measuring instruments. Two GPS antennas will be placed on each satellite. But their position will not be left to chance; the position of the antennas is particularly important because it has a significant impact on the efficiency and accuracy of the measurements. Radiation interacting between the satellite and the antenna can also impair the readings. The engineers therefore have to shield the antennas from this type of interference in the best possible way without reducing the overall performance of the antennas.
Researchers at the Fraunhofer-Chalmers Centre FCC in Gothenburg, a sister institute of the Fraunhofer Institute for Industrial Mathematics ITWM, have found a solution to these problems. "We have developed a software program called Efield in collaboration with universities, SAAB, Ericsson and Efield," says Dr. Fredrik Edelvik of the FCC.
"It allows us to simulate complex antenna systems in great detail. SAAB Space advised us on the Swarm project. We used a CAD model - that is, a computer-based model of the satellites and the antenna. Complex algorithms enabled us to simulate the behavior of the electromagnetic fields and thus determine the optimum position of the antenna and the required shielding." In order to perform these calculations, the research engineers had to develop numerical methods for solving the mathematical equations of the electromagnetic fields. They also needed the powerful performance of a computer with a multi-core processor, enabling them to cut the length of the simulation to just one hour.
The Efield company is now commercializing the software that bears its name.
Thanks to the new simulation methods, ultra-modern antenna systems can be developed in a very short space of time. The engineers save immense costs during the development phase because of less need to carry out expensive tests or to manufacture prototypes. The development phase is also very much shorter, and the antenna systems are ready for market much sooner.