Quantifying Snow Depth Variability within an Airborne FM-CW Snow Radar Footprint

Abstract:

Obtaining timely basin-scale winter and early spring characteristics of snowpack in the Western United States are important for modeling water availability during the melt season. Using an ultra-wideband (UWB) frequency modulated continuous wavelength (FM-CW) airborne radar sensor (2-18 GHz), we are able to map snow depth to an accuracy of 3 cm or less on a basin scale. Supplemental in situ snow density measurements permit snow water equivalent to be determined. The assessment of snow depth from processed radar data requires careful quality control, with precision of the assessment directly related to the time committed to the quality control effort. Given the inherent snow depth variability within a radar footprint (approximately 7m by 70m), a level of precision exceeding the inherent snow depth variability would needlessly delay the preparation of our snow depth data product. This poster presents the results of numerous snow depth measurements conducted on Grand Mesa, Colorado during late January 2020 to assess the inherent snow depth variability within the footprint of our airborne radar, which was collecting data at the same time. We will present our results of inherent snow depth variability, and relate this observed snow depth uncertainty to processed and analyzed radar data to determine an optimum precision for producing our snow depth data product.