基于粗糙海面高度频谱函数的雷达后向散射系数计算

Radar Backscattering Coefficient Calculation Based on Spectrum Function of Sea Surface Elevation

海面雷达后向散射系数是主动微波遥感定量化研究海洋的基础。基于各种海浪谱模式的后向散射系数计算可比性差。鉴于风成粗糙海面的波面斜率呈非Guassian分布的特点 ,本文给出依据自由海面的二维高度谱计算海面的雷达后向散射系数 ,并与实际SIR C/X

Backscattering coefficients play on important role in active microwave remote sensing applications in oceanography. In general, the backscattering coefficients can be calculated from scatter models. But the results are different from the choice of ocean wave spectra that there exist some different forms under some similar wind conditions. Additionally, the models are due to the Gussian distribution of sea surface elevation, which exists only within very low wind condition. Thus model predictions are not faithful reproductions of radar cross section very often. The paper presents a method to calculate the backscattering coefficients with the use of two dimensional spectrum function of sea surface elevation with the prediction of non Gaussian distribution of the elevation and slope of wave surface. Th method does not use a single wave spectrum. The results are comparable with SIR C/X SAR data of South China sea.