SRTM DEM和ASTER GDEM误差的空间分布特征

发布时间：2018-07-11 17:47

本文选题：SRTM + DEM　；参考：《南京师范大学》2017年硕士论文

【摘要】：DEM作为地学分析的输入数据,其精度制约了分析结果的精度,影响着决策的可靠性,因此,DEM的精度评价是地学分析的重要研究内容之一。SRTM DEM和ASTER GDEM具有高精度、高分辨率和开放访问的特点,是目前应用最广泛的DEM数据。诸多学者对其精度进行评价,但多集中在中小区域、典型地形区,尚未对我国区域的SRTM DEM和ASTER GDEM精度评价和误差空间分布展开研究。本文以GLA14高程为假定真值,统计分析SRTM DEM和ASTER GDEM误差在地形因子(坡度、坡向)、地表特征(土地覆盖类型、最大植被覆盖率)、特征地形要素(山脊线、山谷线)影响下的分布规律,运用等经纬度法,研究SRTMDEM和ASTER GDEM误差在我国陆地区域的空间分布特征,运用等面积法和半方差分析法,研究SRTM DEM和ASTER GDEM误差的空间变化情况。主要研究内容和成果如下:1) SRTM DEM和ASTER GDEM误差在我国陆地区域的空间分布特征。SRTM DEM误差在地势平坦区呈菱形分布,在地势复杂区与地形有较强的相关性。ASTER GDEM误差呈条带状分布,条带方向为东北-西南向,与地形相关性较弱。2)地表特征对SRTM DEM和ASTER GDEM误差分布的影响。本文选取土地覆盖类型和最大植被覆盖率等地表特征数据,研究其对DEM误差分布的影响。结果表明,SRTM DEM和ASTER GDEM误差在不同土地覆盖类型的分布有较大差异,与最大植被覆盖率有一定的相关性。3)地形结构对SRTM DEM和ASTER GDEM误差分布的影响。从坡度、坡向、山脊线、山谷线等地形信息,讨论其对DEM误差分布的影响。结果表明:SRTMDEM和ASTERGDM误差分布与坡度、坡向、距离谷脊线的距离有较强的相关性。SRTM DEM和ASTER GDEM误差随着坡度的增大逐渐增大,二者在坡向、距离谷脊线的距离的分布规律相反。4) SRTMDEM和ASTER GDEM误差的空间变异规律。研究轨道运行方向、陆地生态类型和植被覆盖程度对SRTM DEM和ASTER GDEM误差空间变化的影响。结果表明:SRTM DEM和ASTER GDEM误差的半变异值均随着距离的增大而增大。依据稳定时的半变异值将陆地生态类型划分为高、中、低三类,每类的陆地生态类型相同。同一陆地生态类型低植被覆盖的SRTM DEM和ASTER GDEM误差空间变化程度大于高植被覆盖。5)对比分析SRTMDEM和ASTERGDEM误差的空间分布特征。从误差分布规律、误差空间分布、误差空间变异规律三个方面对比分析二者的误差空间分布特征。虽然SRTMDEM和ASTERGDEM误差空间分布特征有差异,但SRTM DEM和ASTERGDEM误差分布规律和空间变异情况相似。同等条件下,SRTM DEM误差比ASTER GDEM小,空间变化程度也较小。
[Abstract]:Dem, as the input data of geoscience analysis, its precision restricts the accuracy of analysis results and affects the reliability of decision making. Therefore, the accuracy evaluation of Dem is one of the important research contents of geoscience analysis. SRTM Dem and ASTER gem have high accuracy. The characteristics of high resolution and open access are the most widely used Dem data. Many scholars have evaluated the accuracy of SRTM Dem and ASTER GDEM, but most of them are concentrated in the small and medium area and typical terrain area. The accuracy evaluation and error spatial distribution of SRTM Dem and ASTER GDEM in our country have not been studied. Taking the GLA14 elevation as the assumed true value, the errors of SRTM Dem and ASTER GDEM are statistically analyzed in terms of terrain factors (slope, slope direction), surface features (land cover type, maximum vegetation coverage), and characteristic terrain elements (ridge line). Under the influence of valley line, the spatial distribution characteristics of SRTMDEM and ASTER GDEM errors in the land area of China are studied by using the method of equal longitude and latitude, and the spatial variation of the errors of SRTM Dem and ASTER gem is studied by using equal area method and semi-variance analysis method. The main contents and results are as follows: 1) the spatial distribution characteristics of SRTM Dem and ASTER GDEM errors in the land area of China. SRTM Dem errors are rhomboid in the flat terrain, and there is a strong correlation between the SRTM Dem error and the terrain in the complex terrain. The direction of the strip is northeast to southwest, and the correlation with topography is weak. 2) the influence of surface features on the error distribution of SRTM Dem and ASTER gem. In this paper, the influence of land cover type and maximum vegetation cover on Dem error distribution is studied. The results show that the distribution of SRTM Dem and ASTER GDEM errors in different land cover types is quite different, and there is a certain correlation between SRTM Dem and ASTER GDEM error distribution, and there is a certain correlation between SRTM Dem and ASTER GDEM error distribution. (3) the influence of terrain structure on SRTM Dem and ASTER GDEM error distribution. From the topographic information of slope, slope direction, ridge line and valley line, the influence of Dem error distribution is discussed. The results show that there is a strong correlation between the error distribution of 1: SRTMDEM and ASTERGDM and the slope, direction, and distance from the valley ridge. The error of SRTM Dem and ASTER GDEM increases with the increase of slope, and they are in the slope direction. The spatial variation of SRTMDEM and ASTER gem errors is opposite to that of valley ridge. The effects of orbit direction, terrestrial ecological types and vegetation coverage on the spatial variation of SRTM Dem and ASTER GDEM errors were studied. The results show that the semi-variances of the error of the two components increase with the increase of the distance. The terrestrial ecological types are divided into three types: high, middle and low, according to the semi-variation values of the stable ones, and the terrestrial ecological types of each type are the same. The spatial variation of SRTM Dem and ASTER GDEM errors in the same terrestrial ecological type was larger than that of high vegetation cover (5. 5) the spatial distribution characteristics of SRTMDEM and ASTERGDEM errors were compared and analyzed. The characteristics of error spatial distribution are compared and analyzed from three aspects: error distribution law, error spatial distribution and error spatial variation law. Although the spatial distribution characteristics of SRTMDEM and ASTERGDEM are different, the distribution of SRTM Dem and ASTERGDEM error is similar to the spatial variation. Under the same conditions, the error of SRTM Dem is smaller than that of ASTER gem, and the spatial variation is smaller.
【学位授予单位】：南京师范大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：P208

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