HR: 08:00h
AN: C41D-01 INVITED     [Abstracts]
TI: Ultra Wideband Radar Mapping of Near Surface Internal Layers: Systems, Results and Analysis
AU: * Gogineni, S
EM: gogineni@ittc.ku.edu
AF: Radar Systems and Remote Sensing Laboratory, The University of Kansas, 2335 Irving Hill Road, Lawrence, KS 66045 United States
AU: Kanagaratnam, P
EM: pkanagar@ittc.ku.edu
AF: Radar Systems and Remote Sensing Laboratory, The University of Kansas, 2335 Irving Hill Road, Lawrence, KS 66045 United States
AU: Parthasarathy, R
EM: parthas@ittc.ku.edu
AF: Radar Systems and Remote Sensing Laboratory, The University of Kansas, 2335 Irving Hill Road, Lawrence, KS 66045 United States
AU: Akins, T L
EM: takins@ittc.ku.edu
AF: Radar Systems and Remote Sensing Laboratory, The University of Kansas, 2335 Irving Hill Road, Lawrence, KS 66045 United States
AU: Braaten, D
EM: braaten@ku.edu
AF: Radar Systems and Remote Sensing Laboratory, The University of Kansas, 2335 Irving Hill Road, Lawrence, KS 66045 United States
AU: Jezek, K C
EM: jezek@iceberg.mps.ohio-state.edu
AF: Byrd Polar Research Center, The Ohio State University, Scott Hall., Columbus, OH 43210 United States
AB: We developed two radar systems for mapping near-surface internal layers. We developed one of these systems to operate over the frequency range 500 to 2000 MHz for surface-based measurements, and the other to operate over the frequency range from 600 to 900 MHz for airborne measurements. Both systems are designed to operate in frequency modulated continuous wave (FM-CW) mode with less than 200 mW of transmit power. We have used the airborne system to collect data over flight lines flown by a NASA P-3 aircraft as a part of NASA's Program for Arctic Regional Climate Assessment (PARCA) initiative during the 2002 and 2003 field seasons. These data show that we can map layers to a depth of about of 150 m in the dry snow zone, 50 m in the percolation zone, and 20 m in the melt zone. During the 2002 field season, one of the flight lines passed over the NASA-U\_1 ice core site with coordinates of $73.84\deg$N and $49.49\deg$W. The ice core was analyzed to determine density at a mean sampling interval of 1.04 m and a variance of 0.05 m. Using these density data, we generated the dielectric profile, which was input into the radar waveform simulator to generate the radar return as a function of depth at the core site. We compared the simulated waveform with the measured data to identify and date a few layers. We tracked the dated layers over a distance of several kilometers to compute spatial and temporal variations in the accumulation rate. During the 2004 field season, we used the surface-based system to collect data over a 10 km x 10 km area at the Summit Camp in Greenland, in conjunction with several in-situ measurements of snow density and layering. The results from the surface-based experiment show that we can map annual layers to a depth of about 200 m and with about 10 cm resolution. We will provide an overview of the radars developed for mapping of near-surface layers and the waveform simulator. We will show results from airborne and surface-based experiments and compare theoretical and experimental data.
DE: 1827 Glaciology (1863)
DE: 1894 Instruments and techniques
SC: Cryosphere [C]
MN: 2004 AGU Fall Meeting