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Re: Radar Pings off ISS



> Navy Satellite Radar at 217 MHz:
>
> On our third attempt we still havent heard anything other than computer
> birdies...

And I just figured out why!... Duh...
I had figured that the +/- 5 KHz doppler all occured during a single
ping (like it does for a typical LEO pass).. so exact tuning wasnt
important....

WRONG.  Now that I think about it, the instantaneous Doppler is only a
function of WHERE and at what angle it goes through the fence and it does
NOT go through the full 10 KHz on a pass like a normal horizon to horizon
LEO pass goes.  We only hear 1 second of a reflection and the
instantaneous Doppler change is insignificant during that instant.

Bottom line.  We must ANTICIPATE the exact Doppler and pre-tune the
receiver to exactly that correct frequency or we wont hear it at all...
Cant wait to try again...

Oh, and you have to vector sum the Doppler from you to the ISS and from
ISS to SPASUR to get the right answer...

Bob


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