Submitted to: International Geoscience and Remote Sensing Symposium Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 5/10/2003
Publication Date: 7/20/2003
Citation: Shi, J., Njoku, E.G., Chen, K.S., Jackson, T.J., O'Neill, P. 2003. Estimation of Soil Moisture with Repeat-Pass L-Band Radiometer Measurements. International Geoscience and Remote Sensing Symposium. 2003. I:413-415. Interpretive Summary:
Technical Abstract: Previous investigations have established the fundamentals of passive microwave remote sensing as an important tool in determining the physical properties of soils. Application of microwave retrieval of soil moisture to hydrological and meteorological sciences has been influenced by the natural variability and complexity of the vegetation canopy and surface roughness that significantly affect the sensitivity of emission measurements to soil moisture. Two possible future spaceborne L-band multi-polarization passive microwave techniques - 2D synthetic aperture interferometry and filled aperture mesh deployable reflectors -- will significantly increase the capability of monitoring Earth's soil moisture globally. In addition to operating at long wavelengths, these multipolarization instruments provide an opportunity to utilize multiple polarization data in the estimation of soil moisture. The full utilization of these data will require a further understanding of surface roughness and vegetation effects on the emission signals, especially on the relationships of the emission signals at different polarizations, in order to develop a quantitative algorithm for global soil moisture mapping. In this study, we evaluate the effect of the surface roughness and vegetation cover on estimating the soil moisture. Based on these characteristics, we demonstrate a technique that uses two repeat-pass measurements from L band radiometer to estimate the soil moisture.