A potential soil moisture product from the HY-2 scanning microwave radiometer

The Chinese HY-2, a satellite designed for ocean dynamic environment monitoring, was launched on August 16, 2011. The onboard scanning microwave radiometer (RM) is primarily designed for the sea surface temperature and wind speed mapping. However, our objective of this investigation is to exploit the large amount of land observations of RM and extend the mission scope to the retrieval of surface soil moisture. The single channel algorithm (SCA) was selected and implemented using only RM observed brightness temperature to estimate surface soil moisture. Ancillary data of vegetation index climatology was used as inputs for the SCA to calculate the vegetation water content, which is a required parameter for vegetation effects correction. The retrieved soil moisture agree in the global pattern of wet and dry regions. Initial assessments were performed using soil moisture measurements by in situ underground sensors over selected networks. Results showed good performance of soil moisture estimation for these land surface conditions for the year of 2012.