Geophysics seminar: Kristine Larson (Colorado Center for Astrodynamic Research) "GPS Can’t Do That, Can It? How making a GPS receiver into a better seismometer led to the development of new snow, soil moisture, vegetation, and water level sensors"

11/19/2019 - 12:00pm
Event Description: 

Talk abstract:

About fifteen years ago I began working on using GPS to measure ground displacements during
large earthquakes. At the time almost all geodesists estimated station positions once per day, as
this is entirely adequate for tectonic applications. Standard geodetic analysis tools (then and
now) ignore the error caused by signals that reflect off the surface below the antenna. Effects of
surface reflections are typically the largest error source in GPS seismology and my group
developed tools to mitigate their impact. That early work in GPS seismology ultimately led us to
develop GPS interferometric reflectometry - where reflected GPS signals are used to turn a GPS
antenna into a bi-static radar. The reflected GPS signals can be used to measure soil moisture,
snow accumulation, tides and storm surges, permafrost melt, and vegetation water content while
simultaneously measuring the positions desired by geodesists. In this talk I will briefly
summarize how GPS is used for tectonic and seismic applications, explain how GPS
interferometric reflectometry works, and then share environmental products that my group has
derived from GPS data.

For more information on this event, contact: 
Ignacio Sepulveda
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