[TenTec] Radio Science + QSK = Radar

[Martin, AA6E]

Joel -

I usually think of "scattering" as  an incoherent process arising from
many small scattering centers (density fluctuations).  When you hear a
clear echo, the response is fairly coherent (with a single delay
value, not too spread out).  It's more like a "reflection" than
(back-)scattering.  Maybe it amounts to the same thing if most of the
scattering centers are at approximately the same range.

I think it is interesting that this kind of physics is accessible to a
ham QSK op with a little aluminum up in the air.  I spent a lot of
years using radiotelescopes that were somewhat more upscale.

73 Martin AA6E

On 1/2/06, joel hallas <jrhallas at optonline.net> wrote:
> It is common indeed. An HF over-the-horizon (OTH) radar guy would call
> it "backscatter" and that is exactly what the Russian (or I should say
> Soviet, I guess) "woodpecker" HF signals of the 70s and 80s were,
> watching us from over there, that made us all a bit crazy.
>
> I never worked on backscatter systems, but was involved with a large
> USAF bistatic "forward scatter" OHD system in the early 70s. It could do
> a good job detecting certain Central Asian events until it was made
> obsolete by satellite observation.
>
> Interestingly another application of forward scatter HF OTH that has
> been verified but not, to my knowledge, used is Tusnami forecasting. An
> HF path, from say WWV to KH6, would show a doppler shift if the ocean
> floor raised (lifting the atmosphere and hence the ionospher ever so
> slightly). This is just what our HF OTH setup was  very good at
> detecting. Not sure exactly why that never took off. A bit off topic I
> guess <g>.
>
> 73 and Happy New Year,
>
> Joel Hallas, W1ZR
>
> ROBERT CARROLL wrote:
>
> >Martin-
> >
--
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