Tuesday 5 June at noon (12:00-13:00) - Askja meeting room on third floor (room 367)
Geodetic Imaging with Interferometric Airborne Radar and Applications to Iceland Glaciers
Radar interferometric systems, either for topographic or surface deformation measurement, have played an increasing role in geodetic imaging of the Earth since the mid 1980s. The Shuttle Radar Topography Mission (SRTM) produced the first globally consistent high resolution digital elevation model of the Earth’s surface and spaceborne repeat pass radar interferometric measurements are a standard tool in the geophysical community for mapping Earth deformation from both natural causes, e.g., earthquakes and volcanoes, and anthropogenic causes, e.g., oil and ground water extraction. Greater flexibility and resolution can be obtained with airborne radar interferometric sensors. Unlike spaceborne sensors both revisit time and viewing geometry can be optimized to a particular application. Airborne sensors such as GeoSAR for topographic measurement and UAVSAR (Uninhabited Aerial Vehicle Synthetic Aperture Radar) for deformation mapping are representative of the capabilities of airborne radar systems for making geodetically relevant measurements. We will provide a brief overview of the UAVSAR instrument and highlight the technical challenges in making airborne repeat pass measurements suitable for geodetic imaging. Several examples of geodetic imaging by UAVSAR will be presented showing the application or airborne repeat pass imaging to geodesy. The second part of the talk we be an extended discussion of use of UAVSAR data in measuring glacier motion in Iceland and some interesting geophysical signatures found in the inteferoemtric and polarimetric data that are conjectured to be related to changes in the electrical properties of the ice.
The research described here was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration. It relates to ongoing collaboration between the University of Iceland, NASA, and the California Institute of Technology, with NASA’s UAVSAR imaging of Langjökull and Hofsjökull. UAVSAR is an L-band (24-cm wavelength; 1.25 GHz) repeat-pass-capable, fully polarimetric SAR system currently being flown aboard a Gulfstream III aircraft.
Dr. Scott Hensley is the principle investigator for the UAVSAR program at NASA’s Jet Propulsion Laboratory where he has worked with various SAR systems and data sets since 1992.
Brent Minchew is working toward a PhD at the California Institute of Technology. His research includes the application of polarimetric and interferometric SAR to glaciological studies.