以误差椭圆长半轴表示带宽的线元位置不确定性ε_E模型  

A Positional Uncertainty ε_E Model for Line Segment Considering Error Ellipse Long Semi-axis as Error Band Width

作　　者：张国芹[1] 朱长青[2] 李国重[3] 

机构地区：[1]信息工程大学测绘学院,郑州市陇海中路66号450052 [2]南京师范大学虚拟地理环境教育部重点实验室,南京市文苑路1号210046 [3]信息工程大学理学院,郑州市科学大道62号450001

出　　处：《武汉大学学报（信息科学版）》2010年第4期495-499,共5页Geomatics and Information Science of Wuhan University

基　　金：国家自然科学基金资助项目(40501058)

摘　　要：考虑实用性和合理性,将线元看成离散点的集合,将线的不确定性看成点的不确定性的聚合体,将线元的位置不确定性模型看成以各点误差椭圆的长半轴E为半径的误差圆的聚合体,建立了以线元上任意点处的误差椭圆的长半轴E为带宽的线元不确定性εE模型。给出了基于该模型衡量线元位置不确定性的三种度量指标:可视化图形、平均误差带宽和误差带的面积。最后,将该模型与εσ模型和εm模型进行了比较。Firstly, we propose a new model named εE model to measure line segments positional uncertainty, which consider the semi long axis of the error ellipse at any point on the line segment as the width of the error band, that is, the positional uncertainty of line segment is considered as a set of error circles with the radius of the error ellipse＇s semi long-axis at any point on the line. Secondly, the analytic expressions of the error band boundary line for the εE model of line segment are deduced, the parameter equations of the error band boundary are gotten. Thirdly, three indexes are given to measure the precision of the line uncertainty based on the εE model： the visualization graph, the average error band width and the error band area. At last, the εE model is compared with the εE model and the εE model. Theory and practice show that εE model is simple in calculation but too limited in the error band width, st. model is scientific in theory but complex in calculation, and model is scientific in theory and convenient in practice though over width in the error band width.

关 键 词：平面线元 位置不确定性 εE模型 误差带 误差椭圆 

分 类 号：P207[天文地球—测绘科学与技术]