<div dir="ltr"><p class="MsoNormal" align="center" style="margin:0in 0in 0.0001pt;font-size:11pt;font-family:Calibri,sans-serif;text-align:center"><span style="font-size:18pt;font-family:'Times New Roman',serif">“Future Concepts in Space Geodesy Using Satellite Constellations”<u></u><u></u></span></p>
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<p class="MsoNormal" align="center" style="margin:0in 0in 0.0001pt;font-size:11pt;font-family:Calibri,sans-serif;text-align:center"><span style="font-size:18pt;font-family:'Times New Roman',serif">Speaker: Dr. Brian Gunter<u></u><u></u></span></p>
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<b><span style="font-family:'Times New Roman',serif"><u></u> <u></u></span></b></p><p class="MsoNormal" style="margin:0in 0in 0.0001pt"><b><font face="Times New Roman, serif"><span style="font-size:14.44444465637207px">Draper Distinguished Speaker series will take place Monday, December 16, 2013 at noon in Room 1409. Feel free to bring lunch.</span></font><br>
</b></p><p class="MsoNormal" style="margin:0in 0in 0.0001pt;font-size:11pt;font-family:Calibri,sans-serif"><br></p><p class="MsoNormal" style="margin:0in 0in 0.0001pt;font-size:11pt;font-family:Calibri,sans-serif"><b><span style="font-family:'Times New Roman',serif">Abstract:<u></u><u></u></span></b></p>
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<span style="font-family:'Times New Roman',serif">The ability to measure temporal gravity field variations from space provides a unique source of information that is critical to understanding the complex processes governing the global water cycle and Earth's response to climate change. Dedicated gravity field missions, such as NASA’s Gravity Recovery and Climate Experiment (GRACE), have demonstrated the value of this time-variable gravity information by revealing a host of new insights into processes such as the seasonal flux of water in the Amazon basin, the loss of ice in Greenland and Antarctica, and the depletion of underground aquifers in Northern India. Despite the tremendous success of GRACE, its temporal resolution is limited to approximately one month, due almost entirely to the limitations of the mission's ground track coverage. There are many mass transport processes (e.g., atmosphere, continental hydrology, non-tidal ocean, etc.) that have cycles much shorter than one month, and which are currently accounted for with models in the GRACE data pre-processing. This highlights the fact that, with only one satellite pair, to get higher spatial resolution, one must sacrifice temporal resolution, and vice-versa; the only way to improve both is to increase the number of satellites involved. This talk will address how this might be achieved through the use of an array of custom-built nanosat class satellites, or through future-planned communication and radio-occultation constellations. The results suggest that such constellations can observe the large-scale (> 1000 km) gravity signals to an accuracy of below 1 mm geoid height at time scales as short as 1 day. In addition, the results would be highly complementary to future dedicated gravity field missions such as GRACE follow-on.<u></u><u></u></span></p>
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<b><i><span style="font-family:'Times New Roman',serif">Biography:<u></u><u></u></span></i></b></p><p class="MsoNormal" style="margin:0in 0in 0.0001pt;font-size:11pt;font-family:Calibri,sans-serif"><b><i><span style="font-family:'Times New Roman',serif"><u></u> <u></u></span></i></b></p>
<p class="MsoNormal" style="margin:0in 0in 0.0001pt;font-size:11pt;font-family:Calibri,sans-serif"><b><i><span style="font-family:'Times New Roman',serif">Dr. Gunter</span></i></b><span style="font-family:'Times New Roman',serif"> is an Assistant Professor in Aerospace Engineering at the Georgia Institute of Technology. He received his B.S. in mechanical engineering from Rice University, and later his M.S. and Ph.D. in aerospace engineering from the University of Texas at Austin, specializing in orbital mechanics. Prior to joining Georgia Tech, Dr. Gunter was on the faculty of the Delft University of Technology (TU-Delft) in the Netherlands, as a member of the Physical and Space Geodesy section. His research activities involve various aspects of spacecraft missions and their applications, such as investigations into current and future laser altimetry missions, monitoring changes in the polar ice sheets using satellite data, applications of satellite constellations, and topics surrounding kinematic orbit determination. He has been responsible for both undergraduate and graduate courses on topics such as satellite orbit determination, Earth and planetary observation, scientific applications of GPS, and space systems design. He is currently a member of the AIAA Astrodynamics Technical Committee, and also serves as the Geodesy chair for the Fall AGU Meeting Program Committee. He has received a NASA group achievement award for his work on the GRACE mission, and he is also a former recipient of a NASA Earth System Science Graduate Fellowship. He is a member of the American Institute of Aeronautics and Astronautics (AIAA), the American Geophysical Union (AGU), and the International Association of Geodesy (IAG).</span></p>
<div><br></div>-- <br>Kerri Cahoy<br>Assistant Professor of Aeronautics and Astronautics<br>Massachusetts Institute of Technology, 37-367<br>77 Massachusetts Ave.<br>Cambridge, MA 02139, USA<br>Cell phone: 650 814-8148<br>
Office phone: 617 324-6005<br>E-mail: <a href="mailto:kcahoy@mit.edu" target="_blank">kcahoy@mit.edu</a>, <a href="mailto:kerri.cahoy@gmail.com" target="_blank">kerri.cahoy@gmail.com</a><br>
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