多基线InSAR最大后验高程反演算法的改进
|
摘要
多基线InSAR是在单基线InSAR的基础上发展一种获取高精度DEM的手段。相较于传统InSAR,多基线InSAR有许多技术上的优势。目前,基于马尔可夫场的最大后验(MRF-MAP)高程反演算法是众多多基线InSAR高程反演算法中精度较高、发展较为成熟的一种。此算法的关键步骤是模型超参数的估计,受制于模型的不完全性和问题的高维特性对超参数的估计只能采用expectation-maximization(EM)算法结合了蒙特卡洛计算方法来进行,因而抽样算法的收敛速度和鲁棒性就成为了影响MRF-MAP精度的关键因素。采用multiple-trial Metropolized independence sampler(MTMIS)抽样代替原始的Metropolis-Hastings抽样。实验结果表明这种改进使样本的收敛速度加快,样本多样性提高,因而能够改进最终获取的DEM的精度。此外,还推导出了超参数估计方差的表达式。
Multi-baseline InSAR is an effective extension of the traditional single baseline InSAR,which can provide highprecision DEM.Among all the reconstruction algorithms,Markov random fields based maximum a posteriori estimation(MRF-MAP)is a robust and precise method.The hyperparameter estimation is a key step of this method which will affect the final DEM accuracy.In practice,the estimation of the hyperparameter is achieved by EM algorithm combined with Monte Carlo methods.In this paper,we utilize the multiple-trial Metropolized independence sampler(MTMIS)instead of Metropolis-Hastings to realize Monte Carlo calculation.The experiment result validate that this improvement can improve the DEM accuracy finally.Moreover,we deduce the estimation variance of the EM step.
Multi-baseline InSAR is an effective extension of the traditional single baseline InSAR,which can provide highprecision DEM.Among all the reconstruction algorithms,Markov random fields based maximum a posteriori estimation(MRF-MAP)is a robust and precise method.The hyperparameter estimation is a key step of this method which will affect the final DEM accuracy.In practice,the estimation of the hyperparameter is achieved by EM algorithm combined with Monte Carlo methods.In this paper,we utilize the multiple-trial Metropolized independence sampler(MTMIS)instead of Metropolis-Hastings to realize Monte Carlo calculation.The experiment result validate that this improvement can improve the DEM accuracy finally.Moreover,we deduce the estimation variance of the EM step.
引文
[1]罗华,雷斌,胡玉新.融合机载高分辨率InSAR数据的DEM生成方法[J].国外电子测量技术,2013,32(8):26-30.
[2]庞蕾,张继贤,范洪冬.多基线干涉SAR测量技术发展与趋势分析[J].电子学报,2010,38(9):2152-2157.
[3]韩晓玲,毛永飞,王静,等.基于多基线InSAR的叠掩区域高程重建方法[J].电子测量技术,2012,35(4):66-70.
[4]FERRAIUOLO G,MEGLIO F,PASCAZIO V,et al.DEM reconstruction accuracy in multichannel SAR interferometry[J].IEEE Transactions on Geoscience and Remote Sensing,2009,47(1):191-201.
[5]张金良,鲁昌华,杨道莲.曲波变换域的SAR图像相干斑去噪[J].电子测量与仪器学报,2013,27(12):1108-1112.
[6]靳国旺,徐青,何钰.机载双天线干涉SAR图像的自动匹配[J].仪器仪表学报,2006,27(增刊1):794-795.
[7]LI S Z.Markov random field modeling in image analysis[M].London:Springer,2009.
[8]陈少华,韩冰,雷斌.SAR海冰MRF分割精度与图像质量的关系研究[J].国外电子测量技术,2013,32(3):31-35.
[9]姚昆,杨学志,唐益明,等.SAR海冰的三维区域MRF图像分割[J].仪器仪表学报,2013,34(11):2551-2557.
[10]袁志辉.多通道干涉SAR关键技术研究[D].北京:中国科学院大学,2013.
[11]LIU J S.Monte Carlo strategies in scientific computing[M].New York:Springer,2008.
[12]张红敏,靳国旺,徐青,等.多基线InSAR干涉图的直接法仿真[J].测绘科学技术学报,2010,27(2):127-130.
[13]耿辉,谢亚楠,王波,等.InSAR测高原理及精度分析[J].电子测量技术,2011,34(2):39-41.
[14]张月婷,丁赤飚,王宏琦,等.基于射线理论的建筑物SAR图像仿真方法[J].国外电子测量技术,2012,31(5):44-48.
[15]FERRAIOLI G.Multichannel InSAR building edge detection[J].IEEE Transactions on Geoscience and Remote Sensing,2010,48(3):1224-1231.
[2]庞蕾,张继贤,范洪冬.多基线干涉SAR测量技术发展与趋势分析[J].电子学报,2010,38(9):2152-2157.
[3]韩晓玲,毛永飞,王静,等.基于多基线InSAR的叠掩区域高程重建方法[J].电子测量技术,2012,35(4):66-70.
[4]FERRAIUOLO G,MEGLIO F,PASCAZIO V,et al.DEM reconstruction accuracy in multichannel SAR interferometry[J].IEEE Transactions on Geoscience and Remote Sensing,2009,47(1):191-201.
[5]张金良,鲁昌华,杨道莲.曲波变换域的SAR图像相干斑去噪[J].电子测量与仪器学报,2013,27(12):1108-1112.
[6]靳国旺,徐青,何钰.机载双天线干涉SAR图像的自动匹配[J].仪器仪表学报,2006,27(增刊1):794-795.
[7]LI S Z.Markov random field modeling in image analysis[M].London:Springer,2009.
[8]陈少华,韩冰,雷斌.SAR海冰MRF分割精度与图像质量的关系研究[J].国外电子测量技术,2013,32(3):31-35.
[9]姚昆,杨学志,唐益明,等.SAR海冰的三维区域MRF图像分割[J].仪器仪表学报,2013,34(11):2551-2557.
[10]袁志辉.多通道干涉SAR关键技术研究[D].北京:中国科学院大学,2013.
[11]LIU J S.Monte Carlo strategies in scientific computing[M].New York:Springer,2008.
[12]张红敏,靳国旺,徐青,等.多基线InSAR干涉图的直接法仿真[J].测绘科学技术学报,2010,27(2):127-130.
[13]耿辉,谢亚楠,王波,等.InSAR测高原理及精度分析[J].电子测量技术,2011,34(2):39-41.
[14]张月婷,丁赤飚,王宏琦,等.基于射线理论的建筑物SAR图像仿真方法[J].国外电子测量技术,2012,31(5):44-48.
[15]FERRAIOLI G.Multichannel InSAR building edge detection[J].IEEE Transactions on Geoscience and Remote Sensing,2010,48(3):1224-1231.