Feasibility Mapping of L‐Band InSAR for SWE Retrievals Across the Western United States

Mountain snowpacks provide vital water resources for communities in the western U.S. (WUS), but high spatial variability challenges accurate measurement of snow water equivalent (SWE) from remote sensing platforms. Studies using repeat airborne L-band (∼25 cm wavelength) Interferometric Synthetic Aperture Radar (InSAR) have demonstrated sensitivity to forest cover fraction (FCF), liquid water content, and incidence angle. We use these factors to map feasibility of L-band InSAR for SWE change (ΔSWE) retrievals in major mountain ecoregions of WUS. We found feasibility declines from ∼65% on 1 February, to 58% on 1 March, and 30% on 1 April, corresponding to 73%, 70%, and 49% of total SWE volume, respectively. Thus, these feasibility maps provide groundwork for future InSAR snow studies using satellite data from missions such as NISAR (NASA-ISRO Synthetic Aperture Radar) to refine work based on regional conditions and hence improve ΔSWE retrievals globally.