ESTIMATION OF SOIL MICROWAVE EFFECTIVE TEMPERATURE AT L-BANDS AND C-BANDS

The soil microwave effective temperature (T-e) is an important paramet er which improves the accuracy of the soil surface moisture derived fr om low frequency microwave radiometric observations, A new semi-empiri cal model of T-e at L- and C-bands is proposed, The model is based on the following inputs: the air temperature (T-a), a deep soil temperatu re (T-d), and the microwave brightness temperature measured at X band (lambda congruent to 3 cm) and V polarization (T-BXV), Unlike other ap proaches based on the surface temperature (T-s), the proposed model ca n be implemented without being dependent on the clear sky conditions r equired to measure T-s with a spaceborne infrared radiometer, However, the proposed model may also use T-s when available, The model was des igned from a large data set simulated by a physical model for smooth b are soil. The model of T-e was then successfully validated with experi mental data acquired during a ground based experiment with the multifr equency PORTOS radiometer. This model designed from smooth soil data w as successfully tested on rough bare soil using experimental data.