AGU member since 1984. Fellow, American Geophysical Union, 2006. Geodesist at the Harvard-Smithsonian Center for Astrophysics and Lecturer on Earth and Planetary Sciences at Harvard University. Major area of interest is the application of space geodesy together with technique development and accuracy improvement to a variety of geoscience problems including tectonics, glacial isostasy, sea level and climate change, and atmospheric sensing. B.S., 1981, Michigan State University; Ph.D., 1986, Massachusetts Institute of Technology. Member of the International Union of Radio Science, founding president of UNAVCO, Inc., service on four IAG special study groups, chair of the PBO data analysis working group. Authored 71 refereed publications, 40 in AGU journals or books. Editor's Citation for Excellence in Refereeing, Journal of Geophysical Research-Solid Earth; National Research Council Postdoctoral Research Associateship; two NASA Group Achievement Awards; 2000 William Bowie Lecturer. AGU service as Associate Editor for Journal of Geophysical Research-Solid Earth.