Passive microwave sensing of soil moisture under vegetation canopies

Abstract

Vegetation cover has a significant effect on the ability of passive microwave radiometers to detect changes in near‐surface soil moisture. A quantitative technique for isolating the effect of vegetation was developed using a theoretical model as the basis of a parametric approach. This approach was evaluated using data collected by truck‐mounted sensors over experimental plots. Results show that a microwave radiometer operating at a 21‐cm wavelength can provide volumetric surface soil moisture estimates to ∼5% of accuracy for fields covered with moderate vegetation. In addition, all of the data required for applying the parametric model can be measured using remote sensing. This paper is not subject to U.S. copyright. Published in 1982 by the American Geophysical Union.