2 ) radar incidence angle and surface roughness correction : to make radar incidence correction and eliminate the surface roughness effects , a wide range of surface parameters ( soil moisture , surface rms height , correlation length , incidence angle ) was input to the ibm model to simulate the effect of surface roughness and radar incidence angle on the sensitivity of soil moisture to the radar backscattering coefficient . a simple model was established to simulate the effects of incidence angle and surface roughness . 3 ) establishment of soil moisture change inversion model : according to a modified ibm model simulation results , the bare surface backscattering coefficients can be expressed as a funtion of the dielectric component for a given surface roughness when the surface slope greater than 2 . 0 , which is valid for most nature surface : in above equation , r0 is the surface reflectivity at normal incidence 本研究中，首先利用基于微波辐射传输方程的微波植被模型和积分方程( iem )模型模拟了各种地表土壤水分含量情况下，植被覆盖、地表粗糙度(包括地表均方根高度和相关长度) 、雷达入射角对c波段(频率4 . 7ghz )水平极化( hh )雷达后向散射系数的影响，在此基础上，建立模型消除了植被覆盖、地表粗糙度、及雷达入射角对雷达后向散射的影响，利用多时相50m分辨率radarsatscansar雷达后向散射系数图像反演得到了地表土壤水分变化模式信息。
By driving expressions and using the method in numerical integration , the results of numerical calculations are analyzed , discussed and contrasted with different conditions , and they showed that there are evident differences in the mean attenuation , scattering , and back scattering cross sections of oblate spheroid particles when the variance is so small that it is near to zero namely it is the same as the rotatory axes are parallel with one direction and when h - polarized and v - polarized incident waves happened . these differences are depended on the relative differences in the average orientation of rotatory axes and the polarized directions of incident wave 通过公式推导和数值积分计算并对结果做了讨论和分析，对比各种情况表明：扁椭球粒子群在方差很小接近为0时，与粒子群旋转轴一致取向的情况相同，入射波水平极化和垂直极化时的平均衰减截面、平均散射截面、平均后向散射截面有明显的不同，这决定于旋转轴平均取向和入射波极化方向的相对差异。
