干涉雷达遥感技术及其在地学信息提取中的应用

干涉雷达遥感技术是一种用于测量高程、地面位移和地表变化的全新技术。它利用合成孔径雷达回波的相位信息 ,通过对同一地区进行的至少两次满足干涉条件的观测 ,获取其干涉相位和干涉图 ,进而获取 DEM或进行差分处理。文章详细介绍了干涉雷达技术原理 ,讨论干涉雷达处理的基本条件 ,分析基线、时间对干涉雷达处理的影响以及干涉雷达技术的误差考虑 ,并按步骤介绍干涉雷达技术在地学信息提取中的一个应用 DEM提取。

INTERFEROMATIC SAR(INSAR) AND ITS APPLICATION TO EXTRACTION OF GEOLOGICAL INFORMATION

Interferomatic SAR(INSAR or IFSAR) is a new technique in RS area. It can be used to survey elevation and detect movements and changes of earth surface. It is based on the echo's phase information of SAR. Through two or more surveys of the same area which meet the interferomatic condition, the interferomatic phase and interferogram can be achieved. Then, DEM can be calculated and furthermore. Differential interferomatic technique can be developed. This paper introduces the theory of INSAR, discusses the effect which comes along baseline and time interval, and the basic condition which INSAR technique can be put into practice. To apply this new technology to the geological information area, the authors gives an elaborate work flow of DEM-extraction. It mainly contains (1) selection of proper image pair, (2) accurate registration of image pair, (3) calculation of interferogram and flattening of earth curve, (4) enhancement of interferogram and calculation of intensity map, (5) unwrapping of interferogram, (6) precise calculation of baseline model, (7) generation of DEM and (8) conversion of coordinates system. At the end, error analysis of INSAR is performed. 1.7 meters accuracy is calculated theoretically, and 2~20 meters accuracy is validated in practice.