Measurement and simulation of diurnal radiobrightness variations for a bare unfrozen soil

In this paper, experimental studies for bare soil radiobrightnesses at frequency of 6.9 GHz were carried out at a test site with meteorological parameters being registered. On the other hand, temperature and moisture profiles in soil were simulated using the land surface processes. As a result, the temperature and moisture profiles were determined. With these data the radiobrightness patterns could be simulated using the radiation transfer theory. The value of moist soil complex dielectric constant as a function of depth was calculated using the spectroscopic soil dielectric model with the soil bound water influence being taken into account. Finally, diurnal variations of radiobrightnesses were simulated and the results of that simulation were compared with the measured data. The observed and simulated diurnal trends of radiobrightness were found to be in a good agreement, thus proving the land surface processes radiobrightness model coupled with the spectral dielectric model to be an efficient instrument for developing data processing algorithms in radiothermal remote sensing.