Friday, April 1, 2016

Re: [Discuss-gnuradio] radio astronomy fast radio burst

Yes, entirely feasible if you kind of "fudge and pray" on the practical realities.  Even 10,000Jy is a tiny signal when cast in the context of a small antenna (2-3dBi).

But can the technical infrastructure be built with relatively-cheap SDR-based kit, and Gnu Radio?  Absolutely.

 

 

 

On 2016-04-01 11:14, Dan McKenna wrote:

Marcus,    Thank you for your replies    Yes, No way with a dipole at a signal flux of 30J    In discussions with two of our faculty members I was told that  the bursts can be 10,000 J and attempts to find an afterglow  have not yielded certain results.    it is not known if any big antenna was really pointing at the burst such  that the real gain of the antenna relative to the source position is known.    This project is looking for the Big Bursts     Yes the V/UHF bands are very busy so the big key is the identification of   a burst that sweeps through the 10 Mhz bandwidth within certain criteria.      The network would then be used to further process events using time of arrival  as the second filter.    We would also like to make this work using two orthogonally polarized antennas     Does this seem more reasonable?    D.              The Lorimer burst was 30Jy peak, lasting only a few milliseconds. You   need instruments with *large* effective apertures to "see" such an     event, and I have doubts about the ability to use a mere ca 20   dipoles globally distributed to synthesize such an aperture.  Most of the     FRB events that have been logged are a *lot* smaller than the Lorimer   event.  Since those stations would likely not be phase-coherent,     then any spectra adding would only improve sensitivity by   sqrt(N)--you don't get to effectively use the sum of the effective   apertures of     the individual stations.    The CHIME observatory, currently entering early operations near   Penticton, BC, has FRBs as a secondary objective, and their antenna     can hardly be described as "a dipole or two".    But, you're the astronomer, so perhaps there's something critical that   I've missed...    

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