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Дата изменения: Unknown Дата индексирования: Sun Apr 10 09:18:31 2016 Кодировка: Поисковые слова: m 63 |
10th of March 2016 |
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Phased array feed shoots down a GPS satellite |
by Greg Hellbourg and Keith Bannister (CASS) |
Phased Array Feeds (PAFs) allow astronomers to 'disappear' radio frequency interference (RFI) from their observations without having to lose their astronomical data. Here, we show images made from a 10 hr observing run with PAF-equipped the Boolardy Engineering Test Array (BETA). BETA observed the well-known radio calibrator PKS 1934-63 at a frequency which is frequently unusable because of transmissions from GPS satellites. The image on the left shows what happens if you don't have any RFI mitigation. It's a mess. The much-improved figure on the right shows PKS 1934-63 right in the center, and is improved because the weights of the phased-array-feed have been adjusted, every few seconds, to steer a null towards nearby satellites. This technique is not possible with traditional single-pixel feeds. More information is available in ACES memo 012.
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