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<p class="MsoNormal">Hi Bob,<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Yes, it is coming up!<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">From the Grape project, we have a well-defined plan for collecting data for the eclipses. This involves listening to approximately 8 kHz around WWV and CHU channels. We have a group right now working on making the RX888/KA9Q emulate the
Grape, and then plan to transition to the new ClementineSDR system as soon as it becomes available. (We are considering calling the FPGA-less USB-based system the ClementineSDR).<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">73 Nathaniel<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal"><b>From:</b> TangerineSDR <tangerinesdr-bounces@lists.tapr.org>
<b>On Behalf Of </b>Bob Stricklin via TangerineSDR<br>
<b>Sent:</b> Thursday, June 8, 2023 9:57 AM<br>
<b>To:</b> TAPR TangerineSDR Modular Software Defined Radio <tangerinesdr@lists.tapr.org><br>
<b>Cc:</b> Bob Stricklin <bstrick@N5BRG.COM><br>
<b>Subject:</b> [TangerineSDR] Project Timing<o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal">The solar Eclipse dates are<o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal">Oct 14 2023<span class="apple-tab-span"> </span> 4 months out<o:p></o:p></p>
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<p class="MsoNormal">Apr 8 2024<span class="apple-tab-span"><o:p></o:p></span></p>
<p class="MsoNormal">10 months out<o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal">To expect to collect data on these events will require using existing hardware and nearly existing software.<o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal">Some time will be needed to define the collection method, train the data collectors, and test the system.<o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal">If an RX888 is to be used it can take 2 weeks to a month to get one of these from China.<o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal">Regarding the comment that the convolution method testing of receiving multiple WWV stations and seeing a difference in timing….<o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal">In addition to atmospheric influenced propogation differences the difference in timing observed may be found to be due to the data processing and timing of the systems which need more study to be understood. Also relativity should be considered.<o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal">The NIST folks have put a lot of effort into making their systems accurate. Best to assume they are accurate.<o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal">Regarding studying phase differences at various frequencies….<o:p></o:p></p>
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<p class="MsoNormal">Phase differences can be studied without having accurate timing marks with a system which is based on streaming the full HF spectrum. More important to have the timing if smaller bandwidths are used.<o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal">Timing data…<o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal">It would be possible to use a IRIG timecode stream which will support a 1 MHz sine wave with AM modulated data and obtain better than 10 us accuracy. This signal can be injected into the RF stream at 1 MHz or mixed up to some other frequency
and level adjusted to match signals of interest. See wikipedia for more details on IRIG and this paper on IRIG Accuracy
<a href="https://ntrs.nasa.gov/api/citations/20190028909/downloads/20190028909.pdf">
https://ntrs.nasa.gov/api/citations/20190028909/downloads/20190028909.pdf</a>.<o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal">System performance….<o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal">Working with a smaller bandwidth may be a better approach. Smaller bandwidth would reduce the burden on the data streaming requirements. Another issue will be defining an antenna which will support the expected bandwidth. Using smaller
bandwidth segments will help with this issue.<o:p></o:p></p>
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<p class="MsoNormal"> <o:p></o:p></p>
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<p class="MsoNormal">Bob N5BRG<o:p></o:p></p>
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