<html><body><div style="font-family: arial, helvetica, sans-serif; font-size: 12pt; color: #000000"><div> <!--StartFragment--><span style="font-family: arial, helvetica, sans-serif; font-size: 12pt;" data-mce-style="font-family: arial, helvetica, sans-serif; font-size: 12pt;">Author: Zuheir Altamimi</span><div style="font-family: Times New Roman; color: #000000; font-size: 16px;" data-mce-style="font-family: Times New Roman; color: #000000; font-size: 16px;"><br><div><div style="direction: ltr; font-family: Tahoma; color: #000000; font-size: 10pt;" data-mce-style="direction: ltr; font-family: Tahoma; color: #000000; font-size: 10pt;"><br><span style="font-family: arial, helvetica, sans-serif; font-size: 12pt;" data-mce-style="font-family: arial, helvetica, sans-serif; font-size: 12pt;">Dear Colleagues,</span><br><br><span style="font-family: arial, helvetica, sans-serif; font-size: 12pt;" data-mce-style="font-family: arial, helvetica, sans-serif; font-size: 12pt;">As part of the 2024 Fall Meeting of the AGU which will be held in Washington, D.C., </span></div><div style="direction: ltr; font-family: Tahoma; color: #000000; font-size: 10pt;" data-mce-style="direction: ltr; font-family: Tahoma; color: #000000; font-size: 10pt;"><span style="font-family: arial, helvetica, sans-serif; font-size: 12pt;" data-mce-style="font-family: arial, helvetica, sans-serif; font-size: 12pt;">09-13 December 2024, </span><span style="font-family: arial, helvetica, sans-serif; font-size: 12pt;" data-mce-style="font-family: arial, helvetica, sans-serif; font-size: 12pt;">we would like to draw your attention to the session on:</span><br><br><span style="font-family: arial, helvetica, sans-serif; font-size: 12pt;" data-mce-style="font-family: arial, helvetica, sans-serif; font-size: 12pt;">G018: Reference Frames: Determination, Usage and Application</span><br><span style="font-family: arial, helvetica, sans-serif; font-size: 12pt;" data-mce-style="font-family: arial, helvetica, sans-serif; font-size: 12pt;"></span></div><div style="direction: ltr; font-family: Tahoma; color: #000000; font-size: 10pt;" data-mce-style="direction: ltr; font-family: Tahoma; color: #000000; font-size: 10pt;"><span style="font-family: arial, helvetica, sans-serif; font-size: 12pt;" data-mce-style="font-family: arial, helvetica, sans-serif; font-size: 12pt;"><br data-mce-bogus="1"></span></div><div style="direction: ltr; font-family: Tahoma; color: #000000; font-size: 10pt;" data-mce-style="direction: ltr; font-family: Tahoma; color: #000000; font-size: 10pt;"><span style="font-family: arial, helvetica, sans-serif; font-size: 12pt;" data-mce-style="font-family: arial, helvetica, sans-serif; font-size: 12pt;">The description of the session is given below.</span><br><br><span style="font-family: arial, helvetica, sans-serif; font-size: 12pt;" data-mce-style="font-family: arial, helvetica, sans-serif; font-size: 12pt;"></span></div><div style="direction: ltr; font-family: Tahoma; color: #000000; font-size: 10pt;" data-mce-style="direction: ltr; font-family: Tahoma; color: #000000; font-size: 10pt;"><span style="font-family: arial, helvetica, sans-serif; font-size: 12pt;" data-mce-style="font-family: arial, helvetica, sans-serif; font-size: 12pt;">We are looking forward to your contribution by submitting an abstract to our session.</span></div><div style="direction: ltr; font-family: Tahoma; color: #000000; font-size: 10pt;" data-mce-style="direction: ltr; font-family: Tahoma; color: #000000; font-size: 10pt;"><span style="font-family: arial, helvetica, sans-serif; font-size: 12pt;" data-mce-style="font-family: arial, helvetica, sans-serif; font-size: 12pt;">Please note the Abstract submission deadline: <strong>Wednesday, 31 July 23:59 EDT/03:59 +1 GMT.</strong></span><br><span style="font-family: arial, helvetica, sans-serif; font-size: 12pt;" data-mce-style="font-family: arial, helvetica, sans-serif; font-size: 12pt;"></span></div><div style="direction: ltr; font-family: Tahoma; color: #000000; font-size: 10pt;" data-mce-style="direction: ltr; font-family: Tahoma; color: #000000; font-size: 10pt;"><span style="font-family: arial, helvetica, sans-serif; font-size: 12pt;" data-mce-style="font-family: arial, helvetica, sans-serif; font-size: 12pt;"><br data-mce-bogus="1"></span></div><div style="direction: ltr; font-family: Tahoma; color: #000000; font-size: 10pt;" data-mce-style="direction: ltr; font-family: Tahoma; color: #000000; font-size: 10pt;"><span style="font-family: arial, helvetica, sans-serif; font-size: 12pt;" data-mce-style="font-family: arial, helvetica, sans-serif; font-size: 12pt;">For more information about the 2024 Fall Meeting, please consult:</span><br><span style="font-family: arial, helvetica, sans-serif; font-size: 12pt;" data-mce-style="font-family: arial, helvetica, sans-serif; font-size: 12pt;">https://www.agu.org/annual-meeting</span><br></div><div style="direction: ltr; font-family: Tahoma; color: #000000; font-size: 10pt;" data-mce-style="direction: ltr; font-family: Tahoma; color: #000000; font-size: 10pt;"><span style="font-family: arial, helvetica, sans-serif; font-size: 12pt;" data-mce-style="font-family: arial, helvetica, sans-serif; font-size: 12pt;"><br data-mce-bogus="1"></span></div><div style="direction: ltr; font-family: Tahoma; color: #000000; font-size: 10pt;" data-mce-style="direction: ltr; font-family: Tahoma; color: #000000; font-size: 10pt;"><span style="font-family: arial, helvetica, sans-serif; font-size: 12pt;" data-mce-style="font-family: arial, helvetica, sans-serif; font-size: 12pt;">Best regards,</span><br><span style="font-family: arial, helvetica, sans-serif; font-size: 12pt;" data-mce-style="font-family: arial, helvetica, sans-serif; font-size: 12pt;">Zuheir Altamimi (IGN-IPGP France)</span><br><span style="font-family: arial, helvetica, sans-serif; font-size: 12pt;" data-mce-style="font-family: arial, helvetica, sans-serif; font-size: 12pt;">Jake Griffiths (US Naval Research Laboratory, Washington, DC, USA)</span><br><span style="font-family: arial, helvetica, sans-serif; font-size: 12pt;" data-mce-style="font-family: arial, helvetica, sans-serif; font-size: 12pt;">Frank Lemoine (NASA Goddard SFC, Greenbelt, MD, USA) </span><br><br><span style="font-family: arial, helvetica, sans-serif; font-size: 12pt;" data-mce-style="font-family: arial, helvetica, sans-serif; font-size: 12pt;"></span></div><div style="direction: ltr; font-family: Tahoma; color: #000000; font-size: 10pt;" data-mce-style="direction: ltr; font-family: Tahoma; color: #000000; font-size: 10pt;"><span style="font-family: arial, helvetica, sans-serif; font-size: 12pt;" data-mce-style="font-family: arial, helvetica, sans-serif; font-size: 12pt;">G018. Reference Frames: Determination, Usage, and Application</span><br><span style="font-family: arial, helvetica, sans-serif; font-size: 12pt;" data-mce-style="font-family: arial, helvetica, sans-serif; font-size: 12pt;"> </span></div><div style="direction: ltr; font-family: Tahoma; color: #000000; font-size: 10pt;" data-mce-style="direction: ltr; font-family: Tahoma; color: #000000; font-size: 10pt;"><br data-mce-bogus="1"></div><div style="direction: ltr; font-family: Tahoma; color: #000000; font-size: 10pt;" data-mce-style="direction: ltr; font-family: Tahoma; color: #000000; font-size: 10pt;"><span style="font-family: arial, helvetica, sans-serif; font-size: 12pt;" data-mce-style="font-family: arial, helvetica, sans-serif; font-size: 12pt;"><!--StartFragment-->The Earth is a dynamic planet. The quantification of many geophysical phenomena, e.g. </span></div><div style="direction: ltr; font-family: Tahoma; color: #000000; font-size: 10pt;" data-mce-style="direction: ltr; font-family: Tahoma; color: #000000; font-size: 10pt;"><span style="font-family: arial, helvetica, sans-serif; font-size: 12pt;" data-mce-style="font-family: arial, helvetica, sans-serif; font-size: 12pt;">sea level variations, co-and post-seismic deformation, glacial isostatic adjustment, local</span><br><span style="font-family: arial, helvetica, sans-serif; font-size: 12pt;" data-mce-style="font-family: arial, helvetica, sans-serif; font-size: 12pt;">subsidence due to natural or anthropogenic causes, loading effects, ice sheet and glacier </span></div><div style="direction: ltr; font-family: Tahoma; color: #000000; font-size: 10pt;" data-mce-style="direction: ltr; font-family: Tahoma; color: #000000; font-size: 10pt;"><span style="font-family: arial, helvetica, sans-serif; font-size: 12pt;" data-mce-style="font-family: arial, helvetica, sans-serif; font-size: 12pt;">mapping, mitigation of natural hazards, but also precise orbit determination of artificial</span><br><span style="font-family: arial, helvetica, sans-serif; font-size: 12pt;" data-mce-style="font-family: arial, helvetica, sans-serif; font-size: 12pt;">satellites, rely on the availability of a global terrestrial reference frame, such as the </span></div><div style="direction: ltr; font-family: Tahoma; color: #000000; font-size: 10pt;" data-mce-style="direction: ltr; font-family: Tahoma; color: #000000; font-size: 10pt;"><span style="font-family: arial, helvetica, sans-serif; font-size: 12pt;" data-mce-style="font-family: arial, helvetica, sans-serif; font-size: 12pt;">International Terrestrial reference Frame (ITRF). The session solicits contributions from </span></div><div style="direction: ltr; font-family: Tahoma; color: #000000; font-size: 10pt;" data-mce-style="direction: ltr; font-family: Tahoma; color: #000000; font-size: 10pt;"><span style="font-family: arial, helvetica, sans-serif; font-size: 12pt;" data-mce-style="font-family: arial, helvetica, sans-serif; font-size: 12pt;">scientists determining or using global reference frames for their applications, focusing on </span></div><div style="direction: ltr; font-family: Tahoma; color: #000000; font-size: 10pt;" data-mce-style="direction: ltr; font-family: Tahoma; color: #000000; font-size: 10pt;"><span style="font-family: arial, helvetica, sans-serif; font-size: 12pt;" data-mce-style="font-family: arial, helvetica, sans-serif; font-size: 12pt;">error budgets and other limiting factors. Papers from analysts of space geodetic techniques </span></div><div style="direction: ltr; font-family: Tahoma; color: #000000; font-size: 10pt;" data-mce-style="direction: ltr; font-family: Tahoma; color: #000000; font-size: 10pt;"><span style="font-family: arial, helvetica, sans-serif; font-size: 12pt;" data-mce-style="font-family: arial, helvetica, sans-serif; font-size: 12pt;">(DORIS, GNSS, SLR, VLBI) and their combination, in the context of the ITRF2020 Updates </span></div><div style="direction: ltr; font-family: Tahoma; color: #000000; font-size: 10pt;" data-mce-style="direction: ltr; font-family: Tahoma; color: #000000; font-size: 10pt;"><span style="font-family: arial, helvetica, sans-serif; font-size: 12pt;" data-mce-style="font-family: arial, helvetica, sans-serif; font-size: 12pt;">are </span><span style="font-family: arial, helvetica, sans-serif; font-size: 12pt;" data-mce-style="font-family: arial, helvetica, sans-serif; font-size: 12pt;">particularly welcome. Papers on the exploitation of past ITRF solutions and the latest 2020 </span></div><div style="direction: ltr; font-family: Tahoma; color: #000000; font-size: 10pt;" data-mce-style="direction: ltr; font-family: Tahoma; color: #000000; font-size: 10pt;"><span style="font-family: arial, helvetica, sans-serif; font-size: 12pt;" data-mce-style="font-family: arial, helvetica, sans-serif; font-size: 12pt;">solutions are also encouraged.<!--EndFragment--> </span><br></div><div style="direction: ltr; font-family: Tahoma; color: #000000; font-size: 10pt;" data-mce-style="direction: ltr; font-family: Tahoma; color: #000000; font-size: 10pt;"><br data-mce-bogus="1"></div><div style="direction: ltr; font-family: Tahoma; color: #000000; font-size: 10pt;" data-mce-style="direction: ltr; font-family: Tahoma; color: #000000; font-size: 10pt;"><br data-mce-bogus="1"></div><div style="direction: ltr; font-family: Tahoma; color: #000000; font-size: 10pt;" data-mce-style="direction: ltr; font-family: Tahoma; color: #000000; font-size: 10pt;"><br data-mce-bogus="1"></div></div></div><!--EndFragment--> </div></div></body></html>