Astronomers at the Murchison Wide-field Array in western Australia have discovered a mysterious TV signal bouncing off an airplane, offering new hope for tackling the growing problem of radio-frequency interference (RFI) that plagues their data. RFI has become increasingly significant as the number of satellites in Earth’s orbit continues to rise.
With 11,330 satellites now in orbit, astronomers are facing an existential crisis due to the increasing interference from these satellite constellations. The MWA, a key telescope for detecting low-frequency radio waves, is particularly affected by this issue.
Researchers Jonathan Pober and Jade Ducharme used a combination of techniques to track down the origin of RFI, including “near-field corrections” and “beamforming.” They successfully identified a stray TV signal reflected off an airplane traveling at 38,400 feet in altitude. The signal was found to be on the frequency band used by Australian digital TV channel 7.
Identifying the source of the RFI opens the door to modeling the interference and recognizing its pattern, allowing for data filtering and preserving more observations. While tracking the source of the RFI is a first step, the next challenge is learning how to remove similar signals from astronomical data.
Pober views this as essential for radio astronomy’s survival, stating that better data analysis techniques are necessary to identify and remove human-generated interference. The researchers’ work has been published in the journal Publications of the Astronomical Society of Australia.
Source: https://www.space.com/space-exploration/tech/astronomers-realize-mysterious-tv-signal-in-their-data-bounced-off-an-airplane