基于合成孔径雷达干涉测量(InSAR)生成DEM实验研究

Experimental Study of Synthetic Aperture Radar Interferometry to Generate DEM

摘要: InSAR作为一种可全天候、全时段、大范围、快速地获取DEM的新兴技术手段，具备影响深远的应用前景；本文针对InSAR技术生成DEM过程中各种类型的误差，采取“多视处理 + 外部DEM辅助”的方法，实现在低空间分辨率的DEM辅助下生成复杂地形区域的数字高程模型，通过评价干涉获取的DEM精度，分析得出InSAR DEM在平坦地区的精度较高，在地形起伏较大的区域因雷达侧视成像机理导致使得相干程度降低，影响了DEM的精度。最后研究了高程精度与地形因素的关系，分析坡度坡向对DEM精度的影响。结果表明，精度随坡度的增加而减小，而坡向的改变对精度影响较小。

Abstract: In this paper, DEM data from the Shuttle Radar Topography Mission (SRTM) was used to assist the generation of InSAR DEM, which is used to remove some interference errors in the process and im-prove the accuracy of DEM generation. Taking the SRTM DEM as the standard, the height difference between two DEM was obtained, and the accuracy of DEM was evaluated. Through analysis, it is con-cluded that the precision of the InSAR DEM in flat area is higher. On the contrary, the precision of DEM in the region of the terrain fluction was proved lower because of decreasing relevance leaded by radar side-view mechanism. In the end, the relationship between elevation accuracy and terrain factors is studied, and the influence of slope and aspect on DEM accuracy is analyzed. The results show that accuracy decreases with the increase of slope, and slope direction changes have little ef-fect on the accuracy.