Estimating snow accumulation and ablation with L-band interferometric synthetic aperture radar (InSAR)

Abstract. Snow is a critical water resource for the western United States and many regions across globe. However, our ability to accurately measure monitor changes in snow mass from satellite remote sensing, specifically its equivalent, remains challenge. To confront these challenges, NASA initiated SnowEx program, multiyear effort address knowledge gaps sensing. During 2020, Uninhabited Aerial Vehicle Synthetic Aperture Radar (UAVSAR) team acquired an L-band interferometric synthetic aperture radar (InSAR) data time series evaluate capabilities limitations of repeat-pass InSAR tracking equivalent (SWE). The goal was develop more comprehensive understanding where when can provide SWE change estimates, allowing community leverage upcoming NASA–ISRO (NASA–Indian Space Research Organization) SAR (NISAR) mission. Our study analyzed three image pairs Jemez Mountains, NM, between 12 26 February 2020. We developed snow-focused multi-sensor method that uses UAVSAR synergistically with optical fractional snow-covered area (fSCA) information. Combining two sensing datasets allows atmospheric correction delineation pixels within swath. For all pairs, we converted phase values estimates acquisition dates. then evaluated InSAR-derived retrievals using combination fSCA, pits, meteorological station data, situ depth sensors, ground-penetrating (GPR). results this show effective estimating both accumulation ablation proper measurement timing, reference phase, snowpack conditions.