Simulation and analysis of microwave emissivity and opacity of winter wheat by radiation transfer method

Measuring soil moisture is very important for monitoring global water cycle. In past years for more than two decades, measuring soil moisture by passive and active microwave remote sensing has been intensively researched. The significant advancements has been made in measuring soil moisture in bare soil field or less vegetation covered region. To measure soil moisture with vegetation cover, vegetation emissivity and opacity have to be included as two parameters to character radiation in vegetation layer. In this paper, we review the phenomenological model to treat radiation transfer in media comprised of vegetation and underlying soil surface. And then simulation of vegetation emissivity and opacity based on radiation transfer theory and combined with input of geometrical parameters and water content measured in winter wheat field was presented. Finally, the relationships between them, in particular of different frequencies and polarization, were been dug out and examined.