Design and evaluation of a fine-resolution radar for mapping near-surface layers using plane-waves

More accurate estimates of snow accumulation fluctuations need to be established for validation of satellite measurements. To validate spaceborne altimeter measurements of mass trends, more information on the nature of spatial accumulation fluctuations is needed. Current methods using ice cores do not reveal enough information on accumulation fluctuations; they provide only mean accumulation and are prone to errors due to sparse sampling.; To aid in the interpretation of satellite data, a 12-18 GHz frequency-modulated continuous-wave radar has been developed to map near-surface layers with 3 cm vertical resolution to a depth of about 20 m. The system has been developed to be mobile and self-contained so that spatial variability of the accumulation over a large area can be characterized. The system employs the use of plane-wave illumination and wide bandwidth to discriminate layers and reject clutter from off-nadir surfaces. The fine-resolution radar has undergone testing in laboratories at the University of Kansas, as well as field experiments conducted at Summit, Greenland, in 2005. The data taken from the field experiment in Greenland have been analyzed and compared to models constructed from actual snow density profiles and stratigraphy taken directly from snow pits. Data processing algorithms have been developed and implemented which account for the system effects and conditions at time of measurement. Layer tracking software has also been developed to aid in the determination of accumulation rates for recent years.; The radar system has also been used at the WAIS Deep Divide in Antarctica during the 2005 field season, and will be used in future field experiments.