<div dir="ltr"><div dir="ltr">All,<div>On a daily basis, starting at at random hours, there are a lot of missing 1 second F values. Carol Finn first noticed the problem. Not so many as to corrupt our 1 minute values, but a fair number. They seem to be concentrated over a 1 -3 hour period, and in the later half of the UT day (after 1300 during the last week or so).</div><div><br></div><div>Whatever is causing this problem, it took September 21 off. During this day, there was on 1 bad 1 second F value.</div><div><br></div><div>In order to see what I describing, you must view a time span of no more than 30 minutes on the Geomag Plots page:</div><div><a href="https://geomag.usgs.gov/plots/">https://geomag.usgs.gov/plots/</a><br></div><div><br></div><div>On the left side of the page, you can select an individual observatory (DED, for your observatory)</div><div><br></div><div>Also, on the left side of the page, there are 2 blocks that signify the start and end time for the horizontal scale. For example, enter a start time of 2018-09-23 20:00:00, and an end time of 2018-09-23 20:30:00. (within the time blocks you can edit the entry already there)</div><div><br></div><div>After selecting this time span, you can use the Step Forward and Step Back 'buttons' to shift the time span accordingly.</div><div><br></div><div>Because of the way this happens for a period of time, and on almost a daily basis, I am of the opinion this is an artificial disturbance, and can be remedied. One of the more probable causes would be welding in the vicinity, but it could be something else.<br><br></div><div>Please investigate at your first opportunity and by all means avoid taking absolute observations during periods where the Total Field values are being corrupted. </div><div><br></div><div>Some statistics:<span style="font-family:Calibri,sans-serif;font-size:11pt"> </span></div><div>
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<p class="MsoNormal" style="margin:0in 0in 0.0001pt;line-height:normal;font-size:11pt;font-family:Calibri,sans-serif">Date</p>
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<p class="MsoNormal" style="margin:0in 0in 0.0001pt;line-height:normal;font-size:11pt;font-family:Calibri,sans-serif">Starting at:</p>
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<p class="MsoNormal" style="margin:0in 0in 0.0001pt;line-height:normal;font-size:11pt;font-family:Calibri,sans-serif">Bad 1 Second F Values</p>
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<p class="MsoNormal" style="margin:0in 0in 0.0001pt;line-height:normal;font-size:11pt;font-family:Calibri,sans-serif">9/19</p>
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<td width="229" valign="top" style="width:171.6pt;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:0in 0in 0.0001pt;line-height:normal;font-size:11pt;font-family:Calibri,sans-serif">1300</p>
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<td width="229" valign="top" style="width:171.65pt;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:0in 0in 0.0001pt;line-height:normal;font-size:11pt;font-family:Calibri,sans-serif">170+</p>
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<p class="MsoNormal" style="margin:0in 0in 0.0001pt;line-height:normal;font-size:11pt;font-family:Calibri,sans-serif">9/20</p>
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<td width="229" valign="top" style="width:171.6pt;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:0in 0in 0.0001pt;line-height:normal;font-size:11pt;font-family:Calibri,sans-serif">1300 UT</p>
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<td width="229" valign="top" style="width:171.65pt;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:0in 0in 0.0001pt;line-height:normal;font-size:11pt;font-family:Calibri,sans-serif">220</p>
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<p class="MsoNormal" style="margin:0in 0in 0.0001pt;line-height:normal;font-size:11pt;font-family:Calibri,sans-serif">9/21</p>
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<td width="229" valign="top" style="width:171.6pt;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:0in 0in 0.0001pt;line-height:normal;font-size:11pt;font-family:Calibri,sans-serif">0100</p>
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<td width="229" valign="top" style="width:171.65pt;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:0in 0in 0.0001pt;line-height:normal;font-size:11pt;font-family:Calibri,sans-serif">1</p>
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<p class="MsoNormal" style="margin:0in 0in 0.0001pt;line-height:normal;font-size:11pt;font-family:Calibri,sans-serif">9/22</p>
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<td width="229" valign="top" style="width:171.6pt;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:0in 0in 0.0001pt;line-height:normal;font-size:11pt;font-family:Calibri,sans-serif">2200</p>
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<td width="229" valign="top" style="width:171.65pt;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:0in 0in 0.0001pt;line-height:normal;font-size:11pt;font-family:Calibri,sans-serif">165</p>
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<td width="229" valign="top" style="width:171.6pt;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:0in 0in 0.0001pt;line-height:normal;font-size:11pt;font-family:Calibri,sans-serif">9/23</p>
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<td width="229" valign="top" style="width:171.6pt;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:0in 0in 0.0001pt;line-height:normal;font-size:11pt;font-family:Calibri,sans-serif">2000</p>
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<td width="229" valign="top" style="width:171.65pt;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:0in 0in 0.0001pt;line-height:normal;font-size:11pt;font-family:Calibri,sans-serif">500+</p>
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<p class="MsoNormal" style="margin:0in 0in 0.0001pt;line-height:normal;font-size:11pt;font-family:Calibri,sans-serif">9/24</p>
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<td width="229" valign="top" style="width:171.6pt;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:0in 0in 0.0001pt;line-height:normal;font-size:11pt;font-family:Calibri,sans-serif">2200</p>
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<td width="229" valign="top" style="width:171.65pt;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:0in 0in 0.0001pt;line-height:normal;font-size:11pt;font-family:Calibri,sans-serif">168</p>
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<p class="MsoNormal" style="margin:0in 0in 0.0001pt;line-height:normal;font-size:11pt;font-family:Calibri,sans-serif">9/25</p>
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<td width="229" valign="top" style="width:171.6pt;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:0in 0in 0.0001pt;line-height:normal;font-size:11pt;font-family:Calibri,sans-serif">2000</p>
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<td width="229" valign="top" style="width:171.65pt;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:0in 0in 0.0001pt;line-height:normal;font-size:11pt;font-family:Calibri,sans-serif">280+</p>
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</tbody></table></div><div><br></div><div><br></div><div>Regards,</div><div>Ed Sauter</div><div>-- <br><div dir="ltr" class="gmail_signature"><span style="color:rgb(80,0,80);font-family:sans-serif;background-color:rgb(255,255,255)">Edward A. Sauter</span><br style="color:rgb(80,0,80);font-family:sans-serif;background-color:rgb(255,255,255)"><span style="color:rgb(80,0,80);font-family:sans-serif;background-color:rgb(255,255,255)">US Geological Survey</span><br style="color:rgb(80,0,80);font-family:sans-serif;background-color:rgb(255,255,255)"><span style="color:rgb(80,0,80);font-family:sans-serif;background-color:rgb(255,255,255)">Box 25046 DFC, MS 966</span><br style="color:rgb(80,0,80);font-family:sans-serif;background-color:rgb(255,255,255)"><span style="color:rgb(80,0,80);font-family:sans-serif;background-color:rgb(255,255,255)">Denver, CO 80226-0046 USA</span><br style="color:rgb(80,0,80);font-family:sans-serif;background-color:rgb(255,255,255)"><span style="color:rgb(80,0,80);font-family:sans-serif;background-color:rgb(255,255,255)">E-mail: </span><a href="mailto:esauter@usgs.gov" style="color:rgb(17,85,204);font-family:sans-serif;background-color:rgb(255,255,255)" target="_blank">esauter@usgs.gov</a><br style="color:rgb(80,0,80);font-family:sans-serif;background-color:rgb(255,255,255)"><span style="color:rgb(80,0,80);font-family:sans-serif;background-color:rgb(255,255,255)">Phone: 303-273-8471</span><br style="color:rgb(80,0,80);font-family:sans-serif;background-color:rgb(255,255,255)"><span style="color:rgb(80,0,80);font-family:sans-serif;background-color:rgb(255,255,255)">Fax 303-273-8506</span>
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