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</o:shapelayout></xml><![endif]--></head><body lang=EN-US link=blue vlink=purple><div class=WordSection1><p class=MsoNormal>All,<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>The clocks in SVN62/PRN01, SVN63/PRN25, and SVN66/PRN27 were all given delta drift offsets ranging from a few to ten parts in 10^19 s/s^2 on 17 July. Because these satellite clocks are relatively very stable as compared to other ground clocks they’ve been carrying ~5% weight in the ensemble (excluding SVN66 which is still subject to rubidium start-up transient) for both IGRT and IGST. While bad data as well as most delta maneuvers and delta clock changes are easy to detect and mitigate automatically in the timescale algorithm, delta drift changes are much less so. Therefore, since 17 July the timescales have suffered in stability and in UTC offset. <o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>To mitigate these effects in the future and to correct data since 17 July I’ve implemented the ability to ingest known delta drift corrections from 2SOPS into the IGS timescales, including the three satellite deltas on 17 July. The ACC will soon resubmit the Rapids and Finals since 17 July to incorporate these corrections and update the relevant Clock RINEX and SP3 files.<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Best regards,<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Ken Senior<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal><span style='font-size:12.0pt;font-family:"Times New Roman","serif";color:black'><o:p> </o:p></span></p><div><div><table class=MsoNormalTable border=1 cellpadding=0 width=450 style='width:337.5pt;border:outset #ECE9D8 1.0pt'><tr><td valign=top style='border:inset #ECE9D8 1.0pt;padding:.75pt .75pt .75pt .75pt'><table class=MsoNormalTable border=0 cellpadding=0><tr><td width=4 style='width:3.0pt;padding:.75pt .75pt .75pt .75pt'></td><td style='padding:.75pt .75pt .75pt .75pt'><p class=MsoNormal><span style='font-size:12.0pt;font-family:"Times New Roman","serif";color:black'><img width=91 height=89 id="_x0000_i1025" src="cid:image001.png@01CE939A.95E96270"></span><span style='font-size:12.0pt;font-family:"Times New Roman","serif";color:black'><o:p></o:p></span></p></td><td valign=bottom style='padding:.75pt .75pt .75pt .75pt'><p class=MsoNormal><b><span style='font-size:12.0pt;font-family:"Verdana","sans-serif";color:black'> Ken L. Senior</span></b><span style='font-size:12.0pt;font-family:"Verdana","sans-serif";color:black'> <br></span><span style='font-size:7.5pt;font-family:"Verdana","sans-serif";color:black'> Advanced Space PNT<br> Naval Center for Space Technology</span><span style='font-size:12.0pt;font-family:"Times New Roman","serif";color:black'> <o:p></o:p></span></p></td></tr></table><p class=MsoNormal><span style='font-size:12.0pt;font-family:"Times New Roman","serif";color:black;display:none'><o:p> </o:p></span></p><table class=MsoNormalTable border=0 cellpadding=0><tr style='height:22.5pt'><td width=20 valign=top style='width:15.0pt;padding:.75pt .75pt .75pt .75pt;height:22.5pt'></td><td valign=top style='padding:.75pt .75pt .75pt .75pt;height:22.5pt'></td><td width=20 valign=top style='width:15.0pt;padding:.75pt .75pt .75pt .75pt;height:22.5pt'></td></tr></table><p class=MsoNormal><span style='font-size:12.0pt;font-family:"Times New Roman","serif";color:black;display:none'><o:p> 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