Sensitivity of a bare soil microwave radiation at L and C-band to variation in soil moisture and soil temperature: the Huntsville ´98 experiment

A comparative evaluation of the potential of L- and C-band passive microwave sensors in estimating soil moisture content was carried out. For this purpose, experimental data collected on a bare soil by ground-based radiometers, during the Huntsville ´98 experiment have been used. The results show the sensitivity of radiation in the C-band (6 cm) and L-band (21 cm) to the changes in water content and soil temperature in bare soil. These data show that the primary parameter affecting the intensity of radiation/brightness temperature in bare soil is the soil moisture. Based on this sensitivity it was feasible to estimate the value of soil moisture without a priori data on the soil parameters. Comparisons of the data collected using different wavelength bands in the dynamic of soil moisture changes inside a fixed antenna footprint are discussed. Additionally, analyses are given of the observed diurnal changes.