矢量GIS环境下多边形叠置中位置误差的传播分析

The analyses of the positional error propagation in overlay operation of polygon under GIS environment

本文首先推导出多边形叠置中两条随机边相交后交点坐标及其方差的计算通式，然后讨论了多边形叠置后交点多边形几何特征（面积和周长）的误差状态，并给出了交点多边形物理特征（重心和质心坐标）的估算解析表达式，最后以三角形和五边形随机叠置为例。

In the overlay operation of polygon ,this paper derives the general formula of intersect point's coordinate and its variance first,then discusses the geometric features' error condition of the new polygon, and gives the analytic expression formulas of barycenter and certriod's coordinates, describes the application method of assessing the new polygon's error condition under GIS environment according to the overlay operation of one triangle and one pentagon.