【摘 要】
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Surface soil moisture is an important parameter in draught monitoring and crop yield estimation,there is an exigent need to obtain spatial-temporal soil moisture information in large range.Microwave s
【机 构】
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Center for Earth Observation and Digital Earth,Chinese Academy of Sciences, Beijing 100094,China
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Surface soil moisture is an important parameter in draught monitoring and crop yield estimation,there is an exigent need to obtain spatial-temporal soil moisture information in large range.Microwave signal is much related to dielectric constant of object observed,and soil dielectric constant is decided by soil moisture,which were the basis of the use of microwave remote sensing technology for soil moisture monitoring.This study focuses on the transformation of soil moisture and soil dielectric constant.The Dobson semi-empirical model was used to build a simulated database,then,the coefficients calibrated of Hallikainen formula by the least square regression method at radiometer SMOS(1.4GHz),AMSR-E(6.9GHz),and scatterometer ERS-WCS and METOP-ASCAT (both at 5.3GHz) frequency-points were performed to set up the simplified models to related the real part of the dielectric constant and the soil volumetric moisture content.The validations are performed using both simulated data of the Dobson model and in-situ observations,the results show that the simplified models have good accuracy and practicality.
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