[amsat-bb] Re: Chipsat

Robert Christ rjc53 at cornell.edu
Wed Jul 14 13:20:38 PDT 2010

We would of course be willing to work with anyone, and offer any help
possible to individuals attempting this task, but this task is
certainly not without its challenges.  The positive side is that while
individual passes may be blind, there are multiple passes, and anyone
interested could try as many times as desired.  As for digitizing the
entire pass band, yes, this is what we are hoping for (though at
200KHz, this shouldn't be more than a few gigs of data).  Of course,
we would be willing to do any additional work in post-processing
necessary, should a ground station be incapable, or partially
successful, with their personal limitations.  If it would help to
modify the data for doppler effects, post-capture, we could
investigate this as well.  There is still planning time before the

"This is certainly a challenging task"
Up to the challenge?
Robert Christ

On Wed, Jul 14, 2010 at 3:39 PM, Howie DeFelice <howied231 at hotmail.com> wrote:
> I may be missing something, but if I understand the following statement correctly:
> "The ChipSats will transmit for approximately 10ms every 1-2 seconds, but the signal is going to be beneath the noise floor. Detecting the signal requires a pseudorandom noise (PRN) code, which Cornell will handle once the dataset is in hand."
> This would require the receiving station to digitize the entire pass band,
> plus and minus doppler, so that Cornell could apply the PRN to pull the signal
> out of the noise floor for demodulation. This is beyond the capability of the "typical"
> ham station but may be practical with some SDR based radios. Not making use of the PRN
> code for the capture will mean that it will be totally blind. i.e. there will be no way
> to know if you are really receiving anything and if the 20 dB antenna was pointed correctly.
> This is certainly a challenging task.
> Howie
> AB2S
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