My group works on high-precision GPS applications, mostly for geoscientists. I started out using GPS to measure plate tectonics, plate boundary deformation, and glacial isostatic adjustment. About ten years ago, I moved on to bigger signals, e.g. ice sheets and volcanoes. In 2003 we started working on our biggest signal (to date), great earthquakes. Here is a page describing some of our results on GPS seismology. There was also a several year diversion into timing and relativistic effects with Judah Levine, Neil Ashby, and John Plumb. With Andria Bilich and Penina Axelrad, I worked on trying to model and remove multipath effects. Here is a multipath map for a GPS site on Mauna Kea, Hawaii. The strong returns (blue sections) correlate with geologic features on the volcano (cinder caps). Removing multipath effects turned out to be very difficult, but that effort led to more successful efforts to use GPS multipath to measure near-surface soil moisture and snow depth.
Here are the things my students, colleagues and I are currently working on:
Research Archives
