综合去取向和广义体散射的三分量极化目标分解模型

Three-component Model-based Decomposition Integrating De-orientation and Generalized Volume Scattering Model

该文深入分析了Freeman分解中存在的体散射过度估计问题,并发展了一种综合去取向理论和广义体散射模型的三分量极化目标分解模型解决该问题。首先,在分解前对极化协方差矩阵进行去取向处理以削弱交叉极化分量;然后采用一种广义体散射模型以适应林地中HH分量和VV分量的比值变化;最后,增加功率限制处理以完全消除负功率问题。实验采用德国Oberpfaffenhofen地区L波段机载ESAR数据进行验证,并与其他改进模型进行比较,结果表明,综合处理后的分解模型能显著地解决体散射过度估计问题,且分解结果更接近地物的实际散射机理。

In this paper, the issue of volume scattering overestimation as all known existing in Freeman decomposition is analyzed in detail, and a three-component decomposition model based on de-orientation and a generalized volume scattering model is presented to reduce the overestimation of volume power. Firstly, de-orientation is applied to the covariance matrix to reduce the volume scattering power before it is decomposed into three scattering components. Secondly, a generalized volume scattering model is adopted by considering the change of HH and VV ratio in different forest areas. In addition, power constrain method is added to eliminate negative power completely. The results are validated by using the L band ESAR data in Oberpfaffenhofen area in Germany and comparing with many other methods. The results show that the integrated model can solve the volume scattering overestimation more notable than other decomposition model, and the results are closer to real scattering type.