Re: Kiwi + Bodnar comparisons looking excellent, while even a Kiwi using internal GPS is good enough for 20M ionospheric doppler measurements

Bryan Klofas

Hey Rob--

Wow, cool! It looks like that is in PST, correct? Sunrise here now is around 7:30am, so just after the sun comes up the ionosphere gets a bit wonky? I guess it's not that much difference.

That's also good that a regular Kiwi with internal GPS is good enough for these measurements.

Thanks, have a great afternoon!
Bryan Klofas KF6ZEO

On 11/28/22 20:20, Rob Robinett wrote:
Hi Bryan,
These charts compare 20M spot frequencies of your Bodnar + Kiwi_0 with the same spots recorded by the Bodnar-driver KFS  Omni_C Bodnar + Kiwi, and with the internal GPS-aided KFS Omni_A Kiwi.
In the first chart you can see in the third row how closely the two GPS-driver Kiwis, located perhaps 30 Km apart, agree about the frequency of the spots they have in common.
In contrast, the second screenshot shows the GPS-aided Kiwi Omni_A has good (+- .25 Hz) agreement with the Bodar driven Kiwis,  but not nearly as good (+-.10 Hz) agreement as with the Bodar-driven KFS Omni_C.
However Gwynn's investigations suggest that doppler shifts of over 1 Hz on 20M are common, so even the Kiwi with internal GPS-aided frequency, calibration seems good enough on GPS-aided Kiwis for meaningful measurements of ionospheric doppler shift.
Rob Robinett
rob@... <mailto:rob@...>
mobile: +1 650 218 8896
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