SMAP L-Band Microwave Radiometer: Instrument Design and First Year on Orbit - Jeffrey R. Piepmeier; Paolo Focardi; Kevin A. Horgan; Joseph J. Knuble; Negar Ehsan; Jared F. Lucey; Clifford Brambora; Paula R. Brown; Pamela J. Hoffman; Richard T. French; Rebecca L. Mikhaylov; Eug-Yun Kwack; et al. (IEEE Trans. Geosci. Remote. Sens., 2017)