I. Introduction
Microwave radiometer (MWR) is designed to obtain radiometric measurements with a combination of frequency and polarization [1]. Due to the continuous, all-weather, all-day observing capabilities, the MWR has been extensively employed in worldwide weather parameters monitoring [2]. The retrieval of meteorological parameters, such as cloud liquid water, total precipitation water, sea wind speed, snow depth, and snow water equivalent, relies tremendously on the MWR instrument [3], [4], [5].