<div dir="ltr"><p class="MsoNormal">Geomag Data Users,<span></span></p>

<p class="MsoNormal">This is a notification of an impending modification to the Boulder
Geomagnetic Observatory (BOU) data set.</p><p class="MsoNormal">  <span></span></p>

<p class="MsoNormal">Geomag Observatory: <b>BOU</b></p>

<p class="MsoNormal">Start Date/Time: 0<b>3/07/2017
– 20:00 UTC</b><span></span></p>

<p class="MsoNormal">This modification is: <b>planned</b>  <span></span></p><p class="MsoNormal"><br></p>

<p class="MsoNormal">NOTES: The sensor at the BOU observatory will be relocated
by about 0.5 meters and reoriented. 
Additionally, significant thermal insulation will be added around the
sensor to further stabilize the temperature.</p><p class="MsoNormal"> 
<span></span></p>

<p class="MsoNormal">The table below details the effects and timelines of this
modification on various geomagnetic data and geomagnetic data products.  <span></span></p>

<table class="gmail-MsoTableGrid" border="1" cellspacing="0" cellpadding="0" width="750" style="width:562.5pt;border-collapse:collapse;border:none">
 <tbody><tr>
  <td width="114" valign="top" style="width:85.5pt;border:1pt solid windowtext;padding:0in 5.4pt">
  <p class="MsoNormal" style="margin-bottom:0.0001pt;line-height:normal"><b>Product<span></span></b></p>
  </td>
  <td width="168" valign="top" style="width:1.75in;border-top:1pt solid windowtext;border-right:1pt solid windowtext;border-bottom:1pt solid windowtext;border-left:none;padding:0in 5.4pt">
  <p class="MsoNormal" style="margin-bottom:0.0001pt;line-height:normal"><b>Effect<span></span></b></p>
  </td>
  <td width="150" valign="top" style="width:112.5pt;border-top:1pt solid windowtext;border-right:1pt solid windowtext;border-bottom:1pt solid windowtext;border-left:none;padding:0in 5.4pt">
  <p class="MsoNormal" style="margin-bottom:0.0001pt;line-height:normal"><b>Estimated Start Date-Time:<span></span></b></p>
  </td>
  <td width="156" valign="top" style="width:117pt;border-top:1pt solid windowtext;border-right:1pt solid windowtext;border-bottom:1pt solid windowtext;border-left:none;padding:0in 5.4pt">
  <p class="MsoNormal" style="margin-bottom:0.0001pt;line-height:normal"><b>Estimated End Date-Time:<span></span></b></p>
  </td>
  <td width="162" valign="top" style="width:121.5pt;border-top:1pt solid windowtext;border-right:1pt solid windowtext;border-bottom:1pt solid windowtext;border-left:none;padding:0in 5.4pt">
  <p class="MsoNormal" style="margin-bottom:0.0001pt;line-height:normal"><b>Notes:<span></span></b></p>
  </td>
 </tr>
 <tr>
  <td width="114" valign="top" style="width:85.5pt;border-right:1pt solid windowtext;border-bottom:1pt solid windowtext;border-left:1pt solid windowtext;border-top:none;padding:0in 5.4pt">
  <p class="MsoNormal" style="margin-bottom:0.0001pt;line-height:normal">Raw<span></span></p>
  </td>
  <td width="168" valign="top" style="width:1.75in;border-top:none;border-left:none;border-bottom:1pt solid windowtext;border-right:1pt solid windowtext;padding:0in 5.4pt">
  <p class="MsoNormal" style="margin-bottom:0.0001pt;line-height:normal">Offsets/Drift/Disturbance<span></span></p>
  </td>
  <td width="150" valign="top" style="width:112.5pt;border-top:none;border-left:none;border-bottom:1pt solid windowtext;border-right:1pt solid windowtext;padding:0in 5.4pt">
  <p class="MsoNormal" style="margin-bottom:0.0001pt;line-height:normal">3/7/2017 – 20:00 UTC<span></span></p>
  </td>
  <td width="156" valign="top" style="width:117pt;border-top:none;border-left:none;border-bottom:1pt solid windowtext;border-right:1pt solid windowtext;padding:0in 5.4pt">
  <p class="MsoNormal" style="margin-bottom:0.0001pt;line-height:normal">3/9/2017 – 12:00 UTC<span></span></p>
  </td>
  <td width="162" valign="top" style="width:121.5pt;border-top:none;border-left:none;border-bottom:1pt solid windowtext;border-right:1pt solid windowtext;padding:0in 5.4pt">
  <p class="MsoNormal" style="margin-bottom:0.0001pt;line-height:normal"><span> </span></p>
  </td>
 </tr>
 <tr>
  <td width="114" valign="top" style="width:85.5pt;border-right:1pt solid windowtext;border-bottom:1pt solid windowtext;border-left:1pt solid windowtext;border-top:none;padding:0in 5.4pt">
  <p class="MsoNormal" style="margin-bottom:0.0001pt;line-height:normal">Adjusted<span></span></p>
  </td>
  <td width="168" valign="top" style="width:1.75in;border-top:none;border-left:none;border-bottom:1pt solid windowtext;border-right:1pt solid windowtext;padding:0in 5.4pt">
  <p class="MsoNormal" style="margin-bottom:0.0001pt;line-height:normal">Outage<span></span></p>
  </td>
  <td width="150" valign="top" style="width:112.5pt;border-top:none;border-left:none;border-bottom:1pt solid windowtext;border-right:1pt solid windowtext;padding:0in 5.4pt">
  <p class="MsoNormal" style="margin-bottom:0.0001pt;line-height:normal">3/7/2017 – 19:00 to 20:00 UTC<span></span></p>
  </td>
  <td width="156" valign="top" style="width:117pt;border-top:none;border-left:none;border-bottom:1pt solid windowtext;border-right:1pt solid windowtext;padding:0in 5.4pt">
  <p class="MsoNormal" style="margin-bottom:0.0001pt;line-height:normal">3/14/2017 – 20:00 UTC<span></span></p>
  </td>
  <td width="162" valign="top" style="width:121.5pt;border-top:none;border-left:none;border-bottom:1pt solid windowtext;border-right:1pt solid windowtext;padding:0in 5.4pt">
  <p class="MsoNormal" style="margin-bottom:0.0001pt;line-height:normal">Time required to establish a new geographical calibration<span></span></p>
  </td>
 </tr>
 <tr>
  <td width="114" valign="top" style="width:85.5pt;border-right:1pt solid windowtext;border-bottom:1pt solid windowtext;border-left:1pt solid windowtext;border-top:none;padding:0in 5.4pt">
  <p class="MsoNormal" style="margin-bottom:0.0001pt;line-height:normal">Quasi Definitive<span></span></p>
  </td>
  <td width="168" valign="top" style="width:1.75in;border-top:none;border-left:none;border-bottom:1pt solid windowtext;border-right:1pt solid windowtext;padding:0in 5.4pt">
  <p class="MsoNormal" style="margin-bottom:0.0001pt;line-height:normal">Possible Outage<span></span></p>
  </td>
  <td width="150" valign="top" style="width:112.5pt;border-top:none;border-left:none;border-bottom:1pt solid windowtext;border-right:1pt solid windowtext;padding:0in 5.4pt">
  <p class="MsoNormal" style="margin-bottom:0.0001pt;line-height:normal">3/7/2017 – 20:00 UTC<span></span></p>
  </td>
  <td width="156" valign="top" style="width:117pt;border-top:none;border-left:none;border-bottom:1pt solid windowtext;border-right:1pt solid windowtext;padding:0in 5.4pt">
  <p class="MsoNormal" style="margin-bottom:0.0001pt;line-height:normal">3/9/2017 – 12:00 UTC<span></span></p>
  </td>
  <td width="162" valign="top" style="width:121.5pt;border-top:none;border-left:none;border-bottom:1pt solid windowtext;border-right:1pt solid windowtext;padding:0in 5.4pt">
  <p class="MsoNormal" style="margin-bottom:0.0001pt;line-height:normal"><span> </span></p>
  </td>
 </tr>
 <tr>
  <td width="114" valign="top" style="width:85.5pt;border-right:1pt solid windowtext;border-bottom:1pt solid windowtext;border-left:1pt solid windowtext;border-top:none;padding:0in 5.4pt">
  <p class="MsoNormal" style="margin-bottom:0.0001pt;line-height:normal">Definitive<span></span></p>
  </td>
  <td width="168" valign="top" style="width:1.75in;border-top:none;border-left:none;border-bottom:1pt solid windowtext;border-right:1pt solid windowtext;padding:0in 5.4pt">
  <p class="MsoNormal" style="margin-bottom:0.0001pt;line-height:normal">Possible Outage<span></span></p>
  </td>
  <td width="150" valign="top" style="width:112.5pt;border-top:none;border-left:none;border-bottom:1pt solid windowtext;border-right:1pt solid windowtext;padding:0in 5.4pt">
  <p class="MsoNormal" style="margin-bottom:0.0001pt;line-height:normal">3/7/2017 – 20:00 UTC<span></span></p>
  </td>
  <td width="156" valign="top" style="width:117pt;border-top:none;border-left:none;border-bottom:1pt solid windowtext;border-right:1pt solid windowtext;padding:0in 5.4pt">
  <p class="MsoNormal" style="margin-bottom:0.0001pt;line-height:normal">3/9/2017 – 12:00 UTC<span></span></p>
  </td>
  <td width="162" valign="top" style="width:121.5pt;border-top:none;border-left:none;border-bottom:1pt solid windowtext;border-right:1pt solid windowtext;padding:0in 5.4pt">
  <p class="MsoNormal" style="margin-bottom:0.0001pt;line-height:normal"><span> </span></p>
  </td>
 </tr>
 <tr>
  <td width="114" valign="top" style="width:85.5pt;border-right:1pt solid windowtext;border-bottom:1pt solid windowtext;border-left:1pt solid windowtext;border-top:none;padding:0in 5.4pt">
  <p class="MsoNormal" style="margin-bottom:0.0001pt;line-height:normal">XYZ<span></span></p>
  </td>
  <td width="168" valign="top" style="width:1.75in;border-top:none;border-left:none;border-bottom:1pt solid windowtext;border-right:1pt solid windowtext;padding:0in 5.4pt">
  <p class="MsoNormal" style="margin-bottom:0.0001pt;line-height:normal">Disturbance/Offset<span></span></p>
  </td>
  <td width="150" valign="top" style="width:112.5pt;border-top:none;border-left:none;border-bottom:1pt solid windowtext;border-right:1pt solid windowtext;padding:0in 5.4pt">
  <p class="MsoNormal" style="margin-bottom:0.0001pt;line-height:normal">3/7/2017 – 20:00 UTC<span></span></p>
  </td>
  <td width="156" valign="top" style="width:117pt;border-top:none;border-left:none;border-bottom:1pt solid windowtext;border-right:1pt solid windowtext;padding:0in 5.4pt">
  <p class="MsoNormal" style="margin-bottom:0.0001pt;line-height:normal">3/14/2017 – 20:00 UTC<span></span></p>
  </td>
  <td width="162" valign="top" style="width:121.5pt;border-top:none;border-left:none;border-bottom:1pt solid windowtext;border-right:1pt solid windowtext;padding:0in 5.4pt">
  <p class="MsoNormal" style="margin-bottom:0.0001pt;line-height:normal">New DECBAS will need to be established, similar to Adjusted<span></span></p>
  </td>
 </tr>
 <tr>
  <td width="114" valign="top" style="width:85.5pt;border-right:1pt solid windowtext;border-bottom:1pt solid windowtext;border-left:1pt solid windowtext;border-top:none;padding:0in 5.4pt">
  <p class="MsoNormal" style="margin-bottom:0.0001pt;line-height:normal">SQ<span></span></p>
  </td>
  <td width="168" valign="top" style="width:1.75in;border-top:none;border-left:none;border-bottom:1pt solid windowtext;border-right:1pt solid windowtext;padding:0in 5.4pt">
  <p class="MsoNormal" style="margin-bottom:0.0001pt;line-height:normal">Offsets/Disturbance/Drift<span></span></p>
  </td>
  <td width="150" valign="top" style="width:112.5pt;border-top:none;border-left:none;border-bottom:1pt solid windowtext;border-right:1pt solid windowtext;padding:0in 5.4pt">
  <p class="MsoNormal" style="margin-bottom:0.0001pt;line-height:normal">3/7/2017 – 20:00 UTC<span></span></p>
  </td>
  <td width="156" valign="top" style="width:117pt;border-top:none;border-left:none;border-bottom:1pt solid windowtext;border-right:1pt solid windowtext;padding:0in 5.4pt">
  <p class="MsoNormal" style="margin-bottom:0.0001pt;line-height:normal">4/9/2017 – 00:00 UTC<span></span></p>
  </td>
  <td width="162" valign="top" style="width:121.5pt;border-top:none;border-left:none;border-bottom:1pt solid windowtext;border-right:1pt solid windowtext;padding:0in 5.4pt">
  <p class="MsoNormal" style="margin-bottom:0.0001pt;line-height:normal">~30 Day filter within the algorithm<span></span></p>
  </td>
 </tr>
 <tr>
  <td width="114" valign="top" style="width:85.5pt;border-right:1pt solid windowtext;border-bottom:1pt solid windowtext;border-left:1pt solid windowtext;border-top:none;padding:0in 5.4pt">
  <p class="MsoNormal" style="margin-bottom:0.0001pt;line-height:normal">SV<span></span></p>
  </td>
  <td width="168" valign="top" style="width:1.75in;border-top:none;border-left:none;border-bottom:1pt solid windowtext;border-right:1pt solid windowtext;padding:0in 5.4pt">
  <p class="MsoNormal" style="margin-bottom:0.0001pt;line-height:normal">Offsets/Disturbance/Drift<span></span></p>
  </td>
  <td width="150" valign="top" style="width:112.5pt;border-top:none;border-left:none;border-bottom:1pt solid windowtext;border-right:1pt solid windowtext;padding:0in 5.4pt">
  <p class="MsoNormal" style="margin-bottom:0.0001pt;line-height:normal">3/7/2017 – 20:00 UTC<span></span></p>
  </td>
  <td width="156" valign="top" style="width:117pt;border-top:none;border-left:none;border-bottom:1pt solid windowtext;border-right:1pt solid windowtext;padding:0in 5.4pt">
  <p class="MsoNormal" style="margin-bottom:0.0001pt;line-height:normal">4/9/2017 – 00:00 UTC<span></span></p>
  </td>
  <td width="162" valign="top" style="width:121.5pt;border-top:none;border-left:none;border-bottom:1pt solid windowtext;border-right:1pt solid windowtext;padding:0in 5.4pt">
  <p class="MsoNormal" style="margin-bottom:0.0001pt;line-height:normal">~30 Day filter within the algorithm<span></span></p>
  </td>
 </tr>
 <tr>
  <td width="114" valign="top" style="width:85.5pt;border-right:1pt solid windowtext;border-bottom:1pt solid windowtext;border-left:1pt solid windowtext;border-top:none;padding:0in 5.4pt">
  <p class="MsoNormal" style="margin-bottom:0.0001pt;line-height:normal">DIST<span></span></p>
  </td>
  <td width="168" valign="top" style="width:1.75in;border-top:none;border-left:none;border-bottom:1pt solid windowtext;border-right:1pt solid windowtext;padding:0in 5.4pt">
  <p class="MsoNormal" style="margin-bottom:0.0001pt;line-height:normal">Offsets/Disturbance/Drift<span></span></p>
  </td>
  <td width="150" valign="top" style="width:112.5pt;border-top:none;border-left:none;border-bottom:1pt solid windowtext;border-right:1pt solid windowtext;padding:0in 5.4pt">
  <p class="MsoNormal" style="margin-bottom:0.0001pt;line-height:normal">3/7/2017 – 20:00 UTC<span></span></p>
  </td>
  <td width="156" valign="top" style="width:117pt;border-top:none;border-left:none;border-bottom:1pt solid windowtext;border-right:1pt solid windowtext;padding:0in 5.4pt">
  <p class="MsoNormal" style="margin-bottom:0.0001pt;line-height:normal">4/9/2017 – 00:00 UTC<span></span></p>
  </td>
  <td width="162" valign="top" style="width:121.5pt;border-top:none;border-left:none;border-bottom:1pt solid windowtext;border-right:1pt solid windowtext;padding:0in 5.4pt">
  <p class="MsoNormal" style="margin-bottom:0.0001pt;line-height:normal">~30 Day filter within the algorithm<span></span></p>
  </td>
 </tr>
 <tr>
  <td width="114" valign="top" style="width:85.5pt;border-right:1pt solid windowtext;border-bottom:1pt solid windowtext;border-left:1pt solid windowtext;border-top:none;padding:0in 5.4pt">
  <p class="MsoNormal" style="margin-bottom:0.0001pt;line-height:normal">DST<span></span></p>
  </td>
  <td width="168" valign="top" style="width:1.75in;border-top:none;border-left:none;border-bottom:1pt solid windowtext;border-right:1pt solid windowtext;padding:0in 5.4pt">
  <p class="MsoNormal" style="margin-bottom:0.0001pt;line-height:normal">NA<span></span></p>
  </td>
  <td width="150" valign="top" style="width:112.5pt;border-top:none;border-left:none;border-bottom:1pt solid windowtext;border-right:1pt solid windowtext;padding:0in 5.4pt">
  <p class="MsoNormal" style="margin-bottom:0.0001pt;line-height:normal"><span> </span></p>
  </td>
  <td width="156" valign="top" style="width:117pt;border-top:none;border-left:none;border-bottom:1pt solid windowtext;border-right:1pt solid windowtext;padding:0in 5.4pt">
  <p class="MsoNormal" style="margin-bottom:0.0001pt;line-height:normal"><span> </span></p>
  </td>
  <td width="162" valign="top" style="width:121.5pt;border-top:none;border-left:none;border-bottom:1pt solid windowtext;border-right:1pt solid windowtext;padding:0in 5.4pt">
  <p class="MsoNormal" style="margin-bottom:0.0001pt;line-height:normal">Not a DST Station<span></span></p>
  </td>
 </tr>
</tbody></table>

<p class="MsoNormal"><span> </span></p>

<p class="MsoNormal">Additional notification will be sent once real-time data
products have been fully restored to normal operation.  Please direct any questions or concerns to <a href="mailto:geomag-data@geohazards.usgs.gov">geomag-data@geohazards.usgs.gov</a>. <span></span></p><div><br></div>-- <br><div class="gmail_signature"><div dir="ltr">Tim White<div>Electrical Engineer, PE</div><div>USGS, Geomagnetism Group</div><div>Cell: 303-881-7445</div><div>Phone: 303-273-8409</div><div><a href="mailto:ttwhite@usgs.gov" target="_blank">ttwhite@usgs.gov</a></div></div></div>
</div>