基于SRTM-ASTER融合数据的河网提取

River Network Extraction Based on SRTM-ASTER Fusion Data

在分析SRTM、ASTER GDEM数据源基本特征的基础上,融合了一种直接面向河网提取的数据——SRTM-ASTER,利用SRTM数据较高的垂直分辨率修正ASTER GDEM,弥补了SRTM水平分辨率上的不足;引入Landsat-8遥感卫星数据提取真实河网,分析在有(无)河网辅助条件下融合数据的提取效果,并以总长度、支流数目、套合差为特征指标进行分析。研究结果表明:1)SRTM-ASTER数据提取的河网能综合SRTM和ASTER GDEM数据的优势,提取精度较好,但河流长度以及支流数目有所减少;2)有河网辅助的条件下,经过AGREE算法进行河网纠正以后,提取结果的精度有显著提高。

Based on the analysis of the basic characteristics of SRTM and ASTER GDEM data sources,this paper directlyextracts river network from SRTM-ASTER fusion data,and uses the high vertical resolution of SRTM data to modify ASTERGDEM,which makes up for the shortage of SRTM horizontal resolution.It introduces landsat-8 remote sensing satellite data to extract the real river network,analyzes the extraction effect of the fusion data with or without the assistance of river networkby using the total length,number of tributaries,and registration difference as the characteristic indexes.The results show that:①the river network extracted from SRTM-ASTER data can integrate the advantages of SRTM and ASTER GDEM data,and the extraction accuracy is better,but the length of river and the number of tributaries are reduced;②under the condition of river network assistance,after the river network correction by AGREE algorithm,the accuracy of extraction results is significantly improved.