Wideband radar for airborne measurements of snow thickness on sea ice
Abstract
Ocean-ice-atmosphere interactions are modulated by snow cover on the sea ice due to the low thermal conductivity and high reflectivity of snow. Current sea ice models use climatological data to simulate a snow cover on the sea ice. Snow cover is also the main source of error in deriving sea ice thickness from freeboard height measurements made by satellite-borne radar and laser altimeters. To improve sea ice models, and, ultimately, global climate models accurate knowledge of snow thickness of sea ice over a large area, with fine spatial resolution is desired. The Center for Remote Sensing of Ice Sheets at the University of Kansas has developed a wideband, frequency-modulated, continuous-wave (FMCW) radar for measuring snow thickness on sea ice from a fast-moving, long-range aircraft. The wideband radar, referred to as the Snow Radar, has been successfully deployed on multiple NASA Operation IceBridge missions. Basic waveform parameters of the Snow Radar are a 2.0 to 6.5 GHz bandwidth with a 250-us pulse length. However, with the FMCW radar architecture intermediate frequencies in the range of 31-62 MHz are digitized. The Snow Radar was designed to operate from a nominal altitude of 1500 ft above ground level, but can withstand +/- 500 ft of altitude variation without tweaking the nominal waveform parameters. Vertical resolution of the Snow Radar in snow, assuming a density of 0.3 g/cm3 and after application of a fast-time Hann window, is approximately 5.25 cm. We will discuss radar hardware, performance specifications, signal processing, measurements attained and provide preliminary results from the 2009-2010 Operation IceBridge missions. Representative Snow Radar processing output from 04/02/09 Thule to Fairbanks flight
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2010
- Bibcode:
- 2010AGUFM.C21D..01P
- Keywords:
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- 0736 CRYOSPHERE / Snow;
- 0750 CRYOSPHERE / Sea ice;
- 0758 CRYOSPHERE / Remote sensing;
- 0794 CRYOSPHERE / Instruments and techniques