Snow Water Equivalent (SWE) is a challenging quantity to estimate using remote sensing techniques, due to snow spatial variability and the influence of substrate, vegetation, and atmospheric properties. Even though snow covered area can be estimated based on optical or microwave remote sensing, and snow depth can be estimated from surface height differencing snow free and snow on conditions using lidar and radar altimetry data reliably, remote sensing of SWE remains a challenge. At NASA Goddard Space Flight Center, a new dual microwave instrument, SWESARR, has been designed and built to remotely observe microwave radiation relevant for SWE retrievals. [photo 4]