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I'll never understand why China spent so much time and money finding the perfect remote karst for radio astronomy and then built a radio-loud amusement park aro

I'll never understand why China spent so much time and money finding the perfect remote karst for radio astronomy and then built a radio-loud amusement park around it. >FAST is also receiving an enormous amount of weak radio frequency interference(RFI). Machine learning techniques were used to mitigate the RFI collected by FAST. This observation served as a test observation and it demonstrated that the majority of RFI was filtered out by the machine learning algorithm and the signal ranking pipeline called Nebula is also compatible with the observational data generated from FAST.

skullone 3y ago
Oh man. RFI can be a bit broad spectrum too. Motors, wifi, lights, phones. Prob gonna be a challenge
shagie 3y ago
Compare when the US built Greenbank they wen the other way with the National Radio Quiet Zone (NRQZ) https://en.wikipedia.org/wiki/United_States_National_Radio_Quiet_Zone https://en.wikipedia.org/wiki/United_States_National_Radio_Q... > The Observatory polices the area actively for devices emitting excessive electromagnetic radiation such as microwave ovens, Wi-Fi access points and faulty electrical equipment and request citizens discontinue their usage. Things like only diesel vehicles (at the time, curious if electric cars are allowed now) because regular combustion engines have spark plugs. I also remember watching a program (NOVA?) where they were interviewing one of the people who as charged with identifying sources. Often they were faulty transformers on electric poles (which got fixed). One time it was a woman's elderly dog that had a heating pad that was noisy (that one he went out and got new heating pad and that cleared it up).
- tivert 3y ago
  > Things like only diesel vehicles (at the time, curious if electric cars are allowed now) because regular combustion engines have spark plugs. IIRC, electric cars are so RF-noisy that manufactures do not include AM radios because of the interference. https://spectrum.ieee.org/am-radio-ev-interference https://spectrum.ieee.org/am-radio-ev-interference
  - parkererway 3y ago
    My Nissan Leaf from 2014 has an AM radio, it seems to work fine.
dudisubekti 3y ago
FAST is just some 7km away from a city (Tangbianzhen 塘边镇), and is sorrounded by villages. Human settlements are very radio loud. If they already can manage radio signals from their sorroundings, I don’t see why an amusement park should be any more challenging for them…
- ninjin 3y ago
  Got me interested in exploring the surroundings, here is an OpenStreetMap link for others who feel the same: https://www.openstreetmap.org/#map=15/25.6513/106.8490 https://www.openstreetmap.org/#map=15/25.6513/106.8490 Likewise, here is a link to the telescope's Wikipedia page: https://en.wikipedia.org/wiki/Five-hundred-meter_Aperture_Spherical_Telescope https://en.wikipedia.org/wiki/Five-hundred-meter_Aperture_Sp...
jl6 3y ago
So is that algorithm the radio equivalent of adaptive optics? Measure the noise and subtract it from the signal? If it’s as effective as claimed, does that open up new areas for siting radio telescopes that might have previously been thought too radio-noisy?
rtuulik 3y ago
> I'll never understand why China spent so much time and money finding the perfect remote karst for radio astronomy and then built a radio-loud amusement park around it. Because it is a prestige project for Chinese government. Any science coming out of that is secondary to that.

skullone 3y ago

Oh man. RFI can be a bit broad spectrum too. Motors, wifi, lights, phones. Prob gonna be a challenge

shagie 3y ago

Compare when the US built Greenbank they wen the other way with the National Radio Quiet Zone (NRQZ) https://en.wikipedia.org/wiki/United_States_National_Radio_Quiet_Zone https://en.wikipedia.org/wiki/United_States_National_Radio_Q... > The Observatory polices the area actively for devices emitting excessive electromagnetic radiation such as microwave ovens, Wi-Fi access points and faulty electrical equipment and request citizens discontinue their usage. Things like only diesel vehicles (at the time, curious if electric cars are allowed now) because regular combustion engines have spark plugs. I also remember watching a program (NOVA?) where they were interviewing one of the people who as charged with identifying sources. Often they were faulty transformers on electric poles (which got fixed). One time it was a woman's elderly dog that had a heating pad that was noisy (that one he went out and got new heating pad and that cleared it up).

tivert 3y ago
> Things like only diesel vehicles (at the time, curious if electric cars are allowed now) because regular combustion engines have spark plugs. IIRC, electric cars are so RF-noisy that manufactures do not include AM radios because of the interference. https://spectrum.ieee.org/am-radio-ev-interference https://spectrum.ieee.org/am-radio-ev-interference
- parkererway 3y ago
  My Nissan Leaf from 2014 has an AM radio, it seems to work fine.

dudisubekti 3y ago

FAST is just some 7km away from a city (Tangbianzhen 塘边镇), and is sorrounded by villages. Human settlements are very radio loud. If they already can manage radio signals from their sorroundings, I don’t see why an amusement park should be any more challenging for them…

ninjin 3y ago
Got me interested in exploring the surroundings, here is an OpenStreetMap link for others who feel the same: https://www.openstreetmap.org/#map=15/25.6513/106.8490 https://www.openstreetmap.org/#map=15/25.6513/106.8490 Likewise, here is a link to the telescope's Wikipedia page: https://en.wikipedia.org/wiki/Five-hundred-meter_Aperture_Spherical_Telescope https://en.wikipedia.org/wiki/Five-hundred-meter_Aperture_Sp...

jl6 3y ago

So is that algorithm the radio equivalent of adaptive optics? Measure the noise and subtract it from the signal? If it’s as effective as claimed, does that open up new areas for siting radio telescopes that might have previously been thought too radio-noisy?

rtuulik 3y ago

> I'll never understand why China spent so much time and money finding the perfect remote karst for radio astronomy and then built a radio-loud amusement park around it. Because it is a prestige project for Chinese government. Any science coming out of that is secondary to that.