摘要
绘制等值线是对各类环境要素进行可视化表达的重要方式之一。根据海渔况预报过程中海水表层温度等海洋环境要素数据多规则网格分布的特点,介绍了四边形进行三角网格化并插值生成原始等值线的过程步骤,并利用Visual C++成功开发了渔场环境要素等值线的绘制模块。同时,针对所生成的原始等值线尖锐角过多、不够光滑的特点,给出了一种在保留原始等值点的基础上,补充等值线顶点个数以消除等值线上尖锐角的新的平滑算法,对其平滑过程进行了理论证明并给出了等温线绘制实例。最后,分析讨论了与商业化软件ArcView中的等值线绘制效果差异及其优点。
Isoline drawing is one of the important methods of environmental factor visualization. According to the distribution characteristics of ocean environmental information such as SST and chlorophyll, which can be obtained in the form of two dimensional matrix, regular triangle network can be directly established and the original isoline can be generated in the triangle network. The module of isoline generating was formulated by the development tool Visual C ＋ ＋ . In order to smooth the original isolines, new key points were repeatedly appended to erase sharp angles of the isolines with the original value points maintained. Then, the smoothing process was further analyzed and an SST isoline chart drawn by this means was given. At last, the difference between this method and the one used in ArcView was also presented.
出处
《上海水产大学学报》
CSCD
北大核心
2005年第4期413-418,共6页
Journal of Shanghai Fisheries University
基金
国家863计划项目(2003AA637030)
农业部海洋与河口渔业重点开放实验室课题(开重03-05)
关键词
渔场环境
等值线
海水表层温度
平滑
fishing ground environment
isoline
sea surface temperature
smoothing
