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<p class="MsoNormal">To all:<o:p></o:p></p>
<p class="MsoNormal">A short note about some discussions we had in last night’s TangerineSDR design telco:<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<ol style="margin-top:0in" start="1" type="1">
<li class="MsoListParagraph" style="margin-left:0in;mso-list:l0 level1 lfo1">We plan to provide an operating mode for the Tangerine Data Engine (DE) to run
<a href="https://www.redrapids.com/images/whitepapers/TWP-000-001-R00.pdf">VITA-49</a> compliant. When connected to the Tangerine Local Host (LH) single board computer (SBC), it will run VITA-49-T, a modification of VITA-49 that supports multiple interleaved
channels in a single data stream (without the use of Channel Tags). Attached is an update to the DE-LH protocol which gives details (provided in both MS-Word and pdf, with simple change tracking activated). Note: if you review the spec update and recognize
a problem, please advise, so that I can address it.<o:p></o:p></li><li class="MsoListParagraph" style="margin-left:0in;mso-list:l0 level1 lfo1">We have identified 2 use cases for the Tangerine SDR to upload spectrum data to the Central Host:<o:p></o:p></li><ol style="margin-top:0in" start="1" type="a">
<li class="MsoListParagraph" style="margin-left:0in;mso-list:l0 level2 lfo1">On Demand. In this case, the TangerineSDR saves data to a local ring buffer, and sends a simple heartbeat to the Central system every minute or so. If a superuser at Central Control
needs some data to be uploaded (e.g., a solar flare just happened), they can use a command that will prompt the Central Control system to send a data request to all online TangerineSDRs (a response to a heartbeat). The Tangerine will the identify all the files
created during the requested data observation period, compress them using tar, and then upload them. In this case, the user’s internet connection is busy only during the time needed to upload the compressed files.<o:p></o:p></li><li class="MsoListParagraph" style="margin-left:0in;mso-list:l0 level2 lfo1">Continuous. In this case, the user puts the Tangerine into Continuous Upload Mode; the system will then start building a queue of files to be uploaded, and upload them at whatever
rate it supported by the user’s internet connection (which the user can control with the throttle setting). This case is useful when we want users to report on something significant and lengthy (eclipse, storms, other events); this is called a “campaign.”
Again, the user can control how much this upload monopolizes their internet connection (in the case of DSL) using the throttle, but it is possible that the user could store so much data (e.g., activating a lot of channels even when they have a slow internet
connection) that their system runs out of space. We will have to come up with a policy on how we handle such an occurrence.<o:p></o:p></li></ol>
<li class="MsoListParagraph" style="margin-left:0in;mso-list:l0 level1 lfo1">If anyone wishes to experiment with making a FlexRadio output IQ samples, I built a simple system for doing that. This is useful for doing some Doppler tracking using the Tangerine
LH before the DE hardware is ready. You can find the software at <a href="https://github.com/AB4EJ-1/FlexRadioIQ">
https://github.com/AB4EJ-1/FlexRadioIQ</a> .<o:p></o:p></li></ol>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Comments welcome! -73- Bill AB4EJ<o:p></o:p></p>
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