<html xmlns:v="urn:schemas-microsoft-com:vml" xmlns:o="urn:schemas-microsoft-com:office:office" xmlns:w="urn:schemas-microsoft-com:office:word" xmlns:m="http://schemas.microsoft.com/office/2004/12/omml" xmlns="http://www.w3.org/TR/REC-html40">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<meta name="Generator" content="Microsoft Word 15 (filtered medium)">
<style><!--
/* Font Definitions */
@font-face
{font-family:"Cambria Math";
panose-1:2 4 5 3 5 4 6 3 2 4;}
@font-face
{font-family:Calibri;
panose-1:2 15 5 2 2 2 4 3 2 4;}
/* Style Definitions */
p.MsoNormal, li.MsoNormal, div.MsoNormal
{margin:0in;
font-size:11.0pt;
font-family:"Calibri",sans-serif;}
a:link, span.MsoHyperlink
{mso-style-priority:99;
color:blue;
text-decoration:underline;}
span.EmailStyle18
{mso-style-type:personal-reply;
font-family:"Calibri",sans-serif;
color:windowtext;}
.MsoChpDefault
{mso-style-type:export-only;
font-family:"Calibri",sans-serif;}
@page WordSection1
{size:8.5in 11.0in;
margin:1.0in 1.0in 1.0in 1.0in;}
div.WordSection1
{page:WordSection1;}
--></style><!--[if gte mso 9]><xml>
<o:shapedefaults v:ext="edit" spidmax="1026" />
</xml><![endif]--><!--[if gte mso 9]><xml>
<o:shapelayout v:ext="edit">
<o:idmap v:ext="edit" data="1" />
</o:shapelayout></xml><![endif]-->
</head>
<body lang="EN-US" link="blue" vlink="purple" style="word-wrap:break-word">
<div class="WordSection1">
<p class="MsoNormal">Than you, Tom.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Here is the recording: <a href="https://scranton.zoom.us/rec/share/4GkOUFWuCnEmC6eME33F4CrPtCtT6DpdmHa6qnK2YyRBe3nkJ-_mWvNNF6u1yrGY.pFC4xQAdLpj2QNht">
https://scranton.zoom.us/rec/share/4GkOUFWuCnEmC6eME33F4CrPtCtT6DpdmHa6qnK2YyRBe3nkJ-_mWvNNF6u1yrGY.pFC4xQAdLpj2QNht</a>
<br>
<br>
<o:p></o:p></p>
<p class="MsoNormal">73 Nathaniel W2NAF<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<div style="border:none;border-top:solid #E1E1E1 1.0pt;padding:3.0pt 0in 0in 0in">
<p class="MsoNormal"><b>From:</b> TangerineSDR <tangerinesdr-bounces@lists.tapr.org>
<b>On Behalf Of </b>Tom McDermott via TangerineSDR<br>
<b>Sent:</b> Monday, December 7, 2020 10:26 PM<br>
<b>To:</b> TAPR TangerineSDR Modular Software Defined Radio <tangerinesdr@lists.tapr.org><br>
<b>Cc:</b> Tom McDermott <tom.n5eg@gmail.com><br>
<b>Subject:</b> [TangerineSDR] Notes from PSWS / TangerineSDR of 12-07-2020<o:p></o:p></p>
</div>
<p class="MsoNormal"><o:p> </o:p></p>
<div>
<div>
<div>
<div>
<p class="MsoNormal"><o:p> </o:p></p>
</div>
<div>
<div>
<p class="MsoNormal"><o:p> </o:p></p>
</div>
<div>
<p class="MsoNormal">Notes from PSWS / TangerineSDR call of 12-07-2020<o:p></o:p></p>
</div>
<div>
<p class="MsoNormal"><o:p> </o:p></p>
</div>
<div>
<p class="MsoNormal">1. PI-uptime UPS 2.0 being used for power protection of Raspberry-Pi and Magnetometer by several folks:
<a href="https://alchemy-power.com/pi-uptime-ups-2-0/">https://alchemy-power.com/pi-uptime-ups-2-0/</a> <o:p></o:p></p>
</div>
<div>
<p class="MsoNormal">It can use 18650 size Li-FePO4 or Li-Ion/Li-Polymer battery – jumper selectable. (Note: The optimum Li-Ion battery temperature range during charging is quite narrow, between 10°C and 30°C with problems at low temperature (< 0C ), LiFePo3
has a lower charge temperature capability). $57.99 on Amazon.com, $55.99 on tindie. Other battery types can also be used. Board holds two 18650 batteries.<o:p></o:p></p>
</div>
<div>
<p class="MsoNormal"><o:p> </o:p></p>
</div>
<div>
<p class="MsoNormal">2. Discussion on whether the magnetometer should be aligned to magnetic north or true north - pros and cons to each approach. The absolute accuracy of the X, Y, and Z axis does not need to be extremely high because we are looking for the
delta of the 3-dimensional magnetic field vector against the initial installation vector (which we do not want to change over time). Additionally, citizen science groups may not be able to accurately orient the device, so normalization of the as-installed
configuration is desirable.<o:p></o:p></p>
</div>
<div>
<p class="MsoNormal"><o:p> </o:p></p>
</div>
<div>
<p class="MsoNormal">Nathaniel showed a document (IAGA) providing recommendations on how magnetometers should be installed / aligned. It also provides math for translating coordinate systems. Document is at:<o:p></o:p></p>
</div>
<div>
<p class="MsoNormal"><a href="http://www.iaga-aiga.org/data/uploads/pdf/guides/iaga-guide-observatories.pdf">http://www.iaga-aiga.org/data/uploads/pdf/guides/iaga-guide-observatories.pdf</a> <o:p></o:p></p>
</div>
<div>
<p class="MsoNormal">(The document says that either magnetic north or true north are acceptable orientation alignment reference frames.)<o:p></o:p></p>
</div>
<div>
<p class="MsoNormal"><o:p> </o:p></p>
</div>
<div>
<p class="MsoNormal">Dave Witten requested a starting decision on what TengerineSDR should do so he can continue writing the instrument software.<o:p></o:p></p>
</div>
<div>
<p class="MsoNormal"><o:p> </o:p></p>
</div>
</div>
<div>
<p class="MsoNormal"><o:p> </o:p></p>
</div>
<div>
<p class="MsoNormal">-- Tom, N5EG<o:p></o:p></p>
</div>
<div>
<p class="MsoNormal"><o:p> </o:p></p>
</div>
<div>
<p class="MsoNormal"><o:p> </o:p></p>
</div>
</div>
</div>
</div>
</div>
</body>
</html>