Microwave remote sensing of temporal variations of brightness temperature and near-surface soil water content during a watershed-scale field experiment, and its application to the estimation of soil physical properties

Passive microwave airborne remote sensing was employed to collect daily brightness temperature (T-B) and near-surface (0-5 cm depth) soil water content (referred to as "soil water content") data during June 10-18, 1992. in the Little Washita watershed, Oklahoma. A comparison of multitemporal data with the soils data revealed a direct correlation between changes in T-B and soil water content, and soil texture. Regression relationships were developed for the ratio of percent sand to percent clay (RSC) and effective saturated hydraulic conductivity (K-sat) in terms of T-B and soil water content change. Validation of results indicated that both RSC and K-sat can be estimated with adequate accuracy. The relationships are valid for the region with Small variation Of soil organic matter content, soils with fewer macropores, and limiting experimental conditions. However, the findings have potential to employ microwave remote sensing for obtaining quick estimates of soil properties over large areas.