基于ALOS极化干涉SAR数据的DEM提取方法研究

极化干涉理论的发展以及全极化卫星的发射,为极化干涉的研究应用提供了广阔的发展空间,开展极化干涉SAR提取DEM的研究对于解决单极化干涉SAR在植被覆盖区DEM提取精度较低的问题具有重要意义。基于山东泰安地区的一对ALOS PALSAR全极化干涉数据,利用相干性最优方法和最大化相位中心分离的方法获取极化干涉信息,并通过对优化后干涉信息的滤波、解缠、基线精确估计等处理来提取DEM,最后将相干优化的结果与传统HH、HV、VV单极化干涉结果进行对比分析。结果表明:优化方法较单极化干涉方法可以有效降低干涉图的噪声,减少相位解缠的残差点,提高解缠相位的质量,并且不同优化方法之间还存在一定差异,数值半径方法获取的DEM精度要好于其他两种优化方法;通过等值线-Goldstein二级干涉SAR滤波方法可进一步提高单极化和优化干涉图的质量,降低残差点,提高相位质量,在水体覆盖的区域通过滤波窗口的设置可以很好地改善DEM的精度。

Extract DEM from ALOS based on Polarimetric SAR interferometry

The development of theory and technology about Polarimetric SAR Interferometry,provided a broad space in research and application,just one of those applications is extract DEM in vegetation coverage area.In this paper,making use of Singular Value Decomposition,Numerical Radius and Phase Diversity ways to extract DEM with processing of filtering,unwrapped phase,base-line estimation and so on.At the end,compared optimization’ results with the single polarimetric interferometry such as HH,HV and VV. It has been observed that optimization ways can reduce the interferometric noise and the phase unwrapping residuals,and improve the precision of the DEM.Meanwhile,Numerical Radius way has a better result than Singular Value Decomposition and Phase Diversity ways;Interferogram with integrated Contoured Median and Goldstein two-step filter method can further improve and optimize the quality of the interferogram,reduce residual almost,improve the precision of the DEM,but if two-step filter window setting big will affect the area of non-water-covers while can improve the water-covers area.