(meteorobs) Fwd: Re: Negative HF radio meteor reception

[drobnock]

Hi
Please clarify, did you or did you not receive a signature that can be
correlated to a HF ( 20-30 mhz ) emission from a meteor?
>>Tom,
I tried some times to look at short waves signals radiated by meteors,
but with no results until now<<

George John Drobnock

"Jean-L. RAULT" wrote:

>
>
>
>
>
>
>
> Sam, James
>
> The lowest frequencies I used  when observing meteors in forward or
> backscatter mode were 21 and 17 MHz. And it works.
>
> This mailing list does not accept attached documents, so I'm forwarding
> you directly two examples of meteor echoes I recorded in 2006 from a 17
> MHz and from a 21 MHz broadcast transmitter.
>
> Tom,
>
> I tried some times to look at short waves signals radiated by meteors,
> but with no results until now
>
> Regards
>
> Jean-Louis F6AGR
>
>
>
>
>
> Le 02/03/2012 18:48, Sam Barricklow a écrit :
> > Thomas,
> >
> > Due to the lower frequency, the doppler shift is considerably less at
> > HF frequencies than at VHF.  Also, to hear a meteor radio echo that is
> > not "polluted" by either ground wave or sky wave, your receiver must
> > be within the "skip zone" and beyond ground wave distance.  The skip
> > zone is where the skywave is passing above your location on its way to
> > or from the refraction zone in the ionosphere, and before the signal
> > returns to the Earth's surface.
> >
> > The ideal signal source for HF meteor radio echo work would be a
> > shortwave broadcast station that is located over the horizon, too far
> > away for you to hear groundwave and too close for ionospheric
> > propagation to occur.
> >
> > Here's a link to a YouTube video on the subject:
> >
> > http://www.youtube.com/watch?v=xgrxQdRrCRE
> >
> > A limited amount of information is available at the following website:
> >
> > http://sci2.esa.int/leonids/leonids99/leolisten.html
> >
> > WWV in Fort Collins might be useful for you when the MUF (maximum
> > usable frequency) is lower than or near the receive frequency,
> > especially for the 15 and 20 MHz frequencies.  WWV transmits at 2.5,
> > 5, 10, 15 and 20 MHz.
> >
> > Other propagation modes might produce "interference" even when no
> > direct ionospheric or groundwave propagation exists, such as
> > backscatter or even forward scatter, both of which are mostly produced
> > by the ionosphere.  Backscatter from distant mountains or ocean waves
> > may also provide signal reflection / refraction at times.
> > Tropospheric ducting might occasionally allow propagation, but it is
> > more common at VHF and above.
> >
> > Note that refraction produced by meteor trail ionization will normally
> > last longer on HF than on VHF.
> >
> > Sam Barricklow
> >
> > On Mar 2, 2012, at 11:54 AM, Thomas Ashcraft wrote:
> >
> >> I am not aware of any HF radio ( high frequency or decametric  ) direct
> >> emission monitoring of meteors or papers on the subject.
> >
> >
> >
> >
> > _______________________________________________
> > meteorobs mailing list
> > meteorobs at meteorobs.org
> > http://lists.meteorobs.org/mailman/listinfo/meteorobs
>
>
>
>    ----------------------------------------------------------------
> _______________________________________________
> meteorobs mailing list
> meteorobs at meteorobs.org
> http://lists.meteorobs.org/mailman/listinfo/meteorobs
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.meteorobs.org/pipermail/meteorobs/attachments/20120303/00e7262b/attachment-0001.html