This study is focused on a soil moisture retrieval system which uses a microwave emission model based on multi-channel passive microwave measurements. The retrieval system has recently been updated with better parameterizations. The notable improvements to the above system include: (i) new microwave measurement-based input surface soil moisture data, (ii) replacement of the input VWC climatology data set with monthly varying VOD data sets, (iii) implementation of a new calibration technique to calibrate the soil texture and roughness parameter, and (iv) application of rainfall, active snow, RFI and thick vegetation masks based on microwave channels. The recently improved retrieval system produces very reasonable soil moisture results. The results are very preliminary in nature, and require more rigorous quantitative analysis in order to be used for any regional to climate scale applications.