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Re: Navy space radar??



Ronald G. Parsons wrote:
> 
> I have "listened" to many echoes from the NAVSPR transmitter (the one
> near me is Kickapoo near Wichita Falls, TX. By "listen", some of the
> stronger echoes are audible, but many more are visible using FFT
> programs such as FFTDSP which use the sound card.

	By recording (through the night?) using a "VOX" or level-activated
recording program such as "Recall" one may collect many audible echoes.
By treating the resultant wave file with a spectral analysis program,
many interesting and unique characteristics can be seen, and some 
calculations done.  A nifty and truly "free" such program is available
on the internet: "Spectrogram" written by Richard Horne.  A slightly 
modified version, which allows other manipulations is also available
at another site.
	Some echoes received during the Leonid meteor shower were so 
strong they overloaded my system...

> The Doppler shift of Mir is quite large and the passband of the receiver
> very small in comparison. I have never been able to convince myself that
> I have heard the echo from either Mir or the Shuttle. Would love to
> though.

	Ron, I know exactly what you mean. I had no luck hearing 
specific spacecraft such as MIR until I calculated and adjusted 
for the significant doppler(two shifts!)...then I heard them every time,
accurate to within seconds as predicted by an sgp4 algorithm using
elements
less than 24 hours old.  Living relatively near the transmitter site
means
the doppler must be reckoned with or you'll be at the wrong place at
the right time.
	Our narrow passbands throw away lots of the signal.  If anyone
has an ICOM R7000 schematic or extra manual, I'd love to have a copy!
	If you'd like to hear what the radar return from STS-88 sounded
like on my rig, there's a clickable .wav file at the URL I mentioned
in my previous response to Tony's request.

	Bob's comment as to pointing your antenna toward the desired
spacecraft is particularly true if you are relatively close to the
transmitter site.  If you just want to hear some returns, the Wichita
Falls (Kikapoo Lake)transmitter is a good direction to "point" to, and
plenty of outfits fly by in a 24 hour period. Be patient.  Although 
there are three transmitters, this one is supposedly at least 20 times
more powerful than the other two(Arizona and Alabama).

	Good luck to all.

	73,

	Steve  W5ZA  (once WN5ITW)

	Shreveport, La.

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