星载多基线与升降轨InSAR提取DEM方法研究

项目名称： 星载多基线与升降轨InSAR提取DEM方法研究

项目编号： No.41501497

项目类型： 青年科学基金项目

立项/批准年度： 2016

项目学科： 天文学、地球科学

项目作者： 蒋厚军

作者单位： 南京邮电大学

项目金额： 20万元

中文摘要： 星载InSAR是获取全球高分辨率高精度DEM的先进技术手段。在地形复杂地区，多基线和升降轨InSAR能够克服相位解缠困难、叠掩与阴影等问题，但现有实现方法仍存在多基线观测随机过程建模不准确和升降轨高程融合未深入考虑局部几何定位误差等问题,降低了高程估计与融合的精度和可靠性。针对这些问题，本项目将开展多基线与升降轨InSAR提取DEM的新方法研究：在多基线InSAR方面，拟使用多基线干涉协方差矩阵和马尔科夫随机场建立观测随机模型，提高建模的准确性；在升降轨InSAR方面，拟使用点云数据三维表面匹配校正升降轨高程存在的局部几何定位误差，并建立融合模型。在以上理论方法研究的基础上，重点突破协方差矩阵估计、多基线最大后验估计、升轨和降轨高程点云配准、升降轨高程融合最优估计等关键技术，并开展星载SAR数据实验，建立相应的数据处理流程，为我国困难地区地形测绘提供实用可靠的技术手段。

中文关键词： 多基线干涉合成孔径雷达；升降轨数据融合；数字高程模型

英文摘要： Spaceborne SAR interferometry is an advanced technology for global high-resolution DEM generation with high-accuracy. In rough terrain areas, multi-baseline and ascending/descending InSAR can avoid phase unwrapping and remove the voids caused by layover/shadow. However, for multi-baseline InSAR estimation existing stochastic models in analytical form are not accurate enough due to the assumption of point targets scattering. Also, most methods for ascending/descending InSAR data fusion do not consider local positioning errors between the two datasets. These issues reduce the accuracy and reliability of height estimation results. Therefore, in this project we are going to explore new approaches of multi-baseline and ascending/descending InSAR for DEM reconstruction. The multi-baseline observation model will be improved by using covariance matrix and Markov Random Field (MRF); meanwhile the local positioning errors between ascending and descending datasets are corrected by 3D surface matching. Based on these innovative ideas, new models and approaches for multi-baseline estimation and ascending/descending fusion will be built. Key problems to be solved include multi-baseline covariance estimation, MAP(Maximum a posteriori)-MRF solution, ascending/descending point clouds coregistration, optimal estimation for ascending/descending fusion, etc. The new approaches will be applied on spaceborne InSAR data, and corresponding algorithms and processing chain will be developed. This project will provide efficient technical means for topographic mapping in Western China.

英文关键词： multi-baseline interferometric synthetic aperture radar;ascending/descending data fusion;digital elevation model