摘要
利用一组间隔仅为一天的高分辨雷达卫星COSMO-Skymed影像获取西部某山区4个不同分辨率(4 m1、0 m、20 m5、0 m)的数字高程模型(DEM)。由于西部高山空白区缺乏实测资料,所以以航天飞机雷达地形测绘(SRTM)为参考数字高程模型(DEM)并从其中获取较为可靠的足量地面控制点,从图像中选取高坡度、低坡度、低相干性三个区域,分别从坡度、相干性、分辨率三个方面,比较、分析山区DEM的精度。研究表明:利用合成孔径雷达干涉(InSAR)技术获取的与SRTM DEM基本一致;低坡度区域比高坡度区域的精度更高;相比于低坡度地区,高坡度地区的高程差值对分辨率的变化更为敏感;DEM分辨率越高,与SRTM DEM的差值就越大,与SRTM DEM本身的分辨率较小有关;对于低相干区域,其可靠性有待商榷,即使其50 m分辨率的DEM与SRTM DEM也存在较大差距。
The digital elevation Experiments were carried out by using two COSMO-S kymed images with only one day temporal interval to obtain four DEM with different resolutions （4 meters, 10 meters, 20 meters, 50 meters） in a western mountain area. Due to the lack of ground surveying date in western mountainous areas, enough and reliable ground control points were selected from SRTM DEM taken as ground control points. From slope, coherence and resolution three aspects, DEM accuracy of three regions （low slope, high slop and low coherence areas） with different resolutions were compared. The results show that. the low slope region has higher accuracy than the high slope region; compared to low slope region, the height difference in the high slope region more sensitive with resolution; the InSAR DEM with higher resolution, the difference with SRTM DEM is greater, which is related to the low resolution of SRTM DEM; The reliability of the DEM accuracy in low coherence region is questioned, because there is a big gap between SRTM DEM and DEM even with the resolutions of 50 meter.
出处
《全球定位系统》
2011年第3期57-61,共5页
Gnss World of China
基金
国家自然科学基金项目(41071273)
高等学校博士学科点专项科研基金(20090095110002)
国家西部1:50000地形图空白区测图工程子课题资助
矿山空间信息技术国家测绘局重点实验室(河南理工大学)开放基金资助项目(KLM200909)
