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What is the best frequency for detecting audible AM radio signals from magnetars?
On Jul 15, 11:52 am, "George Dishman" wrote
in http://groups.google.com/group/sci.a...2a2a514?hl=en& : http://en.wikipedia.org/wiki/Heliosphere Both the material within the region and the ISM are almost entirely ionised so are in a form known as "plasma", a soup of charged particles. One of the feautures of plasma is that is absorbs low frequency signals below what is called the "plasma cutoff frequency". Basically below the VHF band, space becomes increasingly opaque and signals from stars don't reach us. Then what is the best frequency for detecting audible AM radio signals from magnetars? It seems like a no win-situation here. Too low and plasmas will cut it off. Too high and you lose strength really fast. http://www.terabeam.com/support/calc...space-loss.php From the above link, it seems that a higher-frequency radio wave would lose its strength faster than a lower-frequency radio wave of the same original strength would. At the start of the transmission, both the higher and lower frequencies maybe at the same power [watts-per-meter-squared]. However, the higher frequency will lose its strength -- and likely dissipate into the noise floor -- quicker than the lower-frequency. Hence, reception of higher-frequencies requires that the transmitter and receiver be closer together. |
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What is the best frequency for detecting audible AM radio signals from magnetars?
In rec.radio.amateur.space Radium wrote:
On Jul 15, 11:52 am, "George Dishman" wrote in http://groups.google.com/group/sci.a...2a2a514?hl=en& : snip Then what is the best frequency for detecting audible AM radio signals from magnetars? Radio astronomy http://www.nrao.edu/whatisra/ http://www2.jpl.nasa.gov/radioastronomy/ http://www.haystack.mit.edu/edu/unde..._tutorial.html What it sounds like: http://www.radio-astronomy.net/ Amateur radio astronomy http://www.nitehawk.com/rasmit/ http://www.signalone.com/radioastronomy/telescope/ http://www.radiosky.com/ snip remaining crap -- Jim Pennino Remove .spam.sux to reply. |
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