Radar Sounding and Imaging of Glacial and Sea Ice: Status and Future
Prasad Gogineni, University of Kansas
Friday, February 24, 2012, 3:30pm
This seminar is part of the Jones Seminars on Science, Technology, and Society series
Satellite observations are currently showing that parts of the Greenland and Antarctic ice sheets are undergoing rapid changes, including glacier speed-up in Greenland and ice shelf disintegration in Antarctica. The disintegration is followed by the speed-up of glaciers buttressed by the ice shelves. Information concerning bed conditions and topography is crucial to understanding the processes causing rapid changes and developing improved ice-sheet models. Satellite observations are also revealing that sea ice extent and thickness are decreasing. Thickness of snow over sea ice is important to estimating sea ice thickness from free-board measurements. Radars coupled with advanced signal processing techniques operated on long-range aircraft can be used for characterizing the ice bed and determining snow thickness over large areas. CReSIS developed radar instrumentation that includes systems operating over the frequency range from 140 MHz to 18 GHz. We have been operating these radars on a variety of aircraft to collect data over key areas of the Greenland and Antarctic ice sheets, as well as over Arctic and Antarctic sea ice. We successfully sounded the three most challenging glaciers in Greenland and generated bed topography maps for these glaciers. To reduce surface clutter, we used synthetic aperture radar (SAR) processing in the along-track direction and Minimum Variance Distortionless Response (MVDR) array processing in the cross-track direction. Radars with SAR and array processing enabled the sounding of more than 3-km thick ice from a jet aircraft flying at 9000 m above the ice surface. We demonstrated that we can map near-surface internal layers with fine range resolution of about 5 cm. We also mapped snow thickness over sea ice with radars being operated on long-range aircraft. In this talk, the scientific requirements for acquiring the data needed to develop next-generation ice-sheet models and associated technical challenges will be presented. I will show sample results obtained with current radars over glacial and sea ice. I will also discuss improved systems that can be developed to support future polar scientific research and operational applications.
About the Speaker
Dr. Gogineni is the Deane E. Ackers Distinguished Professor in the Department of Electrical Engineering and Computer Science at the University of Kansas with more than two decades of research and teaching experience in radar remote sensing of the Earth, including polar regions. Dr. Gogineni served as the Director of the Radar Systems and Remote Sensing Laboratory at the University of Kansas before serving as Manager of NASA’s Polar Research Programs during 1997-1999. He is currently the Director of the Center for Remote Sensing of Ice Sheets (CReSIS). Dr. Gogineni and his colleagues at CReSIS have successfully demonstrated SAR imaging of the ice-bed interface and generated fine-resolution 3-D topography of an ice bed. Gogineni received a Ph.D. in electrical engineering from the University of Kansas, Lawrence, Kansas, in 1984. He has authored or co-authored over 90 archival journal publications and more than 200 technical reports and conference presentations. His research interests include the application of radars to the remote sensing of the polar ice sheets, sea ice, ocean, atmosphere, and land. He developed several radar systems currently being used at the University of Kansas for sounding and imaging of polar ice sheets, and has also participated in field experiments in the Arctic and Antarctica. Dr. Gogineni is a Fellow of the IEEE and a member of URSI Commission F, the American Geophysical Union, the International Glaciological Society, and the Remote Sensing and Photogrammetry Society. He was given the NASA Terra Award in 1998. In 2002, he received the Louise Byrd Graduate Educator Award at the University of Kansas and conducted research at the University of Tasmania as a Fulbright Senior Scholar.