In this paper, an empirical methodology to retrieve bare soil moisture by Synthetic Aperture Radar (SAR) is developed. The model is based on Advanced Integral Equation Model (AIEM). Since AIEM cannot express cross-pol...In this paper, an empirical methodology to retrieve bare soil moisture by Synthetic Aperture Radar (SAR) is developed. The model is based on Advanced Integral Equation Model (AIEM). Since AIEM cannot express cross-polarized backscattering coefficients accurately, we propose an empirical model to retrieve soil moisture for bare farmland only with co-polarized SAR data. The soil moisture can be obtained by solving an equation of HH and VV polarized data without any field measurements. Both simulated and real SAR data are used to validate the accuracy of the model. This method is especially effective in a large area where the surface roughness is difficult to be completely measured.展开更多
In this paper, a new approach was introduced to estimate surface soil moisture using alternating polarization （AP） data of ad- vanced synthetic aperture radar （ASAR）. First, synthetic aperture radar （SAR） backsc...In this paper, a new approach was introduced to estimate surface soil moisture using alternating polarization （AP） data of ad- vanced synthetic aperture radar （ASAR）. First, synthetic aperture radar （SAR） backscattering characteristic of bare surface at C band was simulated using advanced integrated equation model （AIEM）, and four bare surface backscattering models with different polarization were established. In addition, with simultaneous equations of the for- mer four formulas, the surface roughness was eliminated, and models used to estimate soil moisture on bare surface were derived from simulated multipolarization and multiangle ASAR-AP data. Based on these, the best combination of polarization and incident angle was determined. Finally, soil moisture in the middle stream of the Heihe River Basin was estimated. The field measured data demonstrated that the proposed method was capable of retrieving surface soil moisture for both sparse grassland and homogeneous farmland area.展开更多
基金Supported by the National Key Basic Research Program of China(2013CB733400)the National Natural Science Foundation of China(Grant Number:41471299)the Key Projects in the National Science and Technology Pillar Program(2012BAH28B03)
基金Supported by the Research Program of Science and Technology at Universities of Inner Mongolia Autonomous Region (NJZZ11069)the Natural Science Foundation of Inner Mongolia Autonomous Region (2011BS0904)
文摘In this paper, an empirical methodology to retrieve bare soil moisture by Synthetic Aperture Radar (SAR) is developed. The model is based on Advanced Integral Equation Model (AIEM). Since AIEM cannot express cross-polarized backscattering coefficients accurately, we propose an empirical model to retrieve soil moisture for bare farmland only with co-polarized SAR data. The soil moisture can be obtained by solving an equation of HH and VV polarized data without any field measurements. Both simulated and real SAR data are used to validate the accuracy of the model. This method is especially effective in a large area where the surface roughness is difficult to be completely measured.
基金Supported by the Knowledge Innovation Program of Chinese Academy of Sciences(XMXX280722)Special Fund of China Institute of Water Resources and Hydropower Research(2011)Open Fund of State Key Laboratory of Remote Sensing Science(OFSLRSS201105)
文摘In this paper, a new approach was introduced to estimate surface soil moisture using alternating polarization （AP） data of ad- vanced synthetic aperture radar （ASAR）. First, synthetic aperture radar （SAR） backscattering characteristic of bare surface at C band was simulated using advanced integrated equation model （AIEM）, and four bare surface backscattering models with different polarization were established. In addition, with simultaneous equations of the for- mer four formulas, the surface roughness was eliminated, and models used to estimate soil moisture on bare surface were derived from simulated multipolarization and multiangle ASAR-AP data. Based on these, the best combination of polarization and incident angle was determined. Finally, soil moisture in the middle stream of the Heihe River Basin was estimated. The field measured data demonstrated that the proposed method was capable of retrieving surface soil moisture for both sparse grassland and homogeneous farmland area.
