Retrieval of Soil Moisture Using Ground-Based Microwave Radiometer

It is well known that microwave emission from soil is very well correlated to its moisture content. One experimental area near Changchun was selected for the research of retrieval of soil moisture from C-band microwave radiometer. Measurements were carried out on bare smooth soils, bare soils with ridge, dry grass covered soils and standing straw covered soils with different view angles. Soil moisture content (SMC) was measured by collecting soil samples. From the analysis of the datasets, it has been confirmed that C-band is sensitive to the SMC and it is affected by the presence of surface roughness and dry vegetation, this effect depends on the vegetation type and structure, it also depends on the view angle. The results show that H polarization is more sensitive to soil moisture and is more applicable to soil moisture retrieval. Different regression models were established according to the different soil surfaces. This paper confirmed the possibility of using satellite microwave radiometer to monitor soil moisture on global or regional scales.