机构地区: 华南农业大学资源环境学院
出 处: 《中国农业大学学报》 2003年第5期26-29,共4页
摘 要: 研究屏幕分辨率和放大倍数对AutoCAD的空间数据屏幕矢量化精度的影响。结果表明 ,屏幕缩放方法对矢量化精度有较大影响 :放大倍数提高使点位中误差和极限误差均下降 ;图形放大则提高了定点精度 ,放大 8~ 10倍以上可以将点位中误差控制在 0 .0 8mm以下 ,即在允许中误差 0 .2mm的 4 0 %以下 ;放大 8~ 10倍是进行屏幕矢量化的最佳方式 ;屏幕分辨率对点位中误差的影响较小。认为地理信息系统空间数据的人工干预屏幕数字化定点精度应该受到重视。 Vectorization precision under different distinguishing and magnifying rates of computer screen was studied with AutoCAD for geography spatial grid image data. The results indicated that the screen magnification methods had great effect on the precision. The errors of mean square and limitation of point position decreased with increasing magnification. High precision was obtained at 8 to 10 times of magnification. The mean square error of the point position could be under 0.08mm, about 40% of the allowed error. The distinguishing rates of computer screen did not produce significant influence on the precision. It is important to concern the precision during manual operation of GIS database.