Analysis of coincident L-band radiometer and radar measurements with respect to soil moisture and vegetation conditions

Active and passive microwave remote sensing data offer complementary information on the properties of the observed scene. This study investigates the relationship of L-band radiometer and radar signals to vegetation and soil during four field campaigns conducted in United States between 1999 and 2008. The study shows complex relationship between radiometer observed reflectivity and radar observed backscatter over various landscapes, as expected. Vegetation classification was attempted with different in situ and remote sensing parameters but only a purely empirical combination of Vegetation Water Content and crosspolarized backscatter was able to successfully divide the observations into broad categories of high and low vegetation. The study suggests that a combination of radar and radiometer signal is necessary for establishing a parameter that can fully describe the vegetation state.