The main thing is that these bursts are *weak* (< 1Jy typically), and *short duration*. Detecting a CW weak source with smaller antennae is feasible, because you can use long integration times. You have no such option here, unless you're talking about hundreds or thousands of dipoles, all phase coherent.
For example, to equal the collecting area of Parkes, you'd need (at 500MHz): Parkes gain: 45dBi Dipole gain: 2.15dBi 45 - 2.15 = 42.85dB(antenna) Almost 20,000 simple half-wave dipole antenna required, and they'd all need to be phase-coherent. If I've botched the math, please correct me. On 2016-04-01 10:20, Alexander Levedahl wrote: > There are 3 options that I can think of: 1) Use multiple SDRs at each > location. 2) Run an optimization algorithm as a post processing step to > figure out what the phase synchronization should be. > 3) If there is a transmitting satellite near there in frequency, use that to > determine what the phase synch should be. > Each of these has a problem. 1) The necessary budget is larger. > > 2) This will be computationally expensive if the feature to search for is > unknown. > 3) The sat signal and the bursts being looked for may propagate through the > ionosphere differently and so this may prove to be unreliable. > > On Fri, Apr 1, 2016 at 9:59 AM, <mle...@ripnet.com> wrote: > > VLBI guys usually have a local H1 maser clock, they go through a complex > synchronization ritual prior to the start of observations. H1 masers have > short-term stability on the order of 1e-16. > > GPS synchronization would be a *starting point* for such things. > > On 2016-04-01 08:42, madengr wrote: > > What would it take to get phase coherency, say at 1 GHz, on a global scale; > short of running cables? I assume with a moderate priced GPSDO one can get > 10E-12 stability, so that would be 0.01 Hz frequency stability at 1 GHz. > Does that mean you can integrate for 10 seconds and stay within 0.1 radian > phase drift? > Lou > > Marcus D. Leech wrote > 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. > > -- > View this message in context: > http://gnuradio.4.n7.nabble.com/radio-astronomy-fast-radio-burst-help-requested-tp59287p59297.html > [1] > Sent from the GnuRadio mailing list archive at Nabble.com. > > _______________________________________________ > Discuss-gnuradio mailing list > Discuss-gnuradio@gnu.org > https://lists.gnu.org/mailman/listinfo/discuss-gnuradio [2] _______________________________________________ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio [2] Links: ------ [1] http://gnuradio.4.n7.nabble.com/radio-astronomy-fast-radio-burst-help-requested-tp59287p59297.html [2] https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
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