全面定量评估DEM精度的缓冲区叠加法研究

抽样的定量评估与目视判读的定性评估是评估DEM精度的常用方法,这些评估方法与DEM的应用需求不相适应。基于空间自相关原理和等高线回放技术,提出了缓冲区叠加法,即对DEM区域的原始等高线与其回放等高线分别进行融合,按高程配对,相同高程等高线进行缓冲区叠加,计算其重叠面积比,并按原始等高线长度进行加权平均,建立评估指标,全面评估研究区DEM的精度。在试验区DEM精度评估中,整体和局部精度评估与等高线叠加目视判读效果接近,表明这是一种简单易行有效的DEM评估方法,该方法可以应用到多种方法生成的DEM精度的定量评估。

Study on Buffer Superposition to Quantitatively Evaluation DEM Precision Completely

The two main kinds of the DEM precision evaluation methods are quantitatively evaluation based on sampling and qualitative evaluation based on visual interpretation,the methods can't completely satisfied for DEM application requirements.this paper proposed buffer superposition based on spatial autocorrelation and contour regression,the procession is :first dissolving and pairing the original contours and the extracting contours based on elevate respectively,then buffer-stacking based on elevate,calculating the ratio of overlapping,weighted average based on original contour length,establishing assessment index,evaluating the precision of DEM of the study region completely.In this paper,the integral or local precision are both very close to the result of visual interpretation,it means that buffer superposition is a simply and effect method of DEM precision evaluation,can applied to quantitatively evaluating the precision of many DEM from different ways.