摘要
墨卡托投影由于其纬度渐长的特性导致在极地海区投影存在严重的长度变形,无法在南北纬80°以外高纬度海区航海图中较好地应用。将长度变形程度明显低于墨卡托投影的等距离正圆柱投影作为极地海区的海图投影,研究了该投影平面中等角航线在极地海区的展绘方法。建立了等距离正圆柱投影平面上等角航线方程并对其曲率进行了分析,推导了绘制一般曲线形态的"以直代曲"公式;最后提出了一种可满足给定精度要求的等角航线展绘算法。实验结果表明:该算法简单易行,可在海图编绘规范规定的误差范围内,实现等角航线的精确展绘。
For meridional parts of Mercator Projection grow rapidly in high latitude, which may result serious distortion in polar sea area and make Mercator Projection not be used in the nautical chart beyond the north and south latitude 80 degrees. Equidistance Cylindrical Projection was taken in the paper whose length distortion is significantly lower than Mercator Projection as polar sea chart projection and studied the method of describing rhumb line in polar sea. Based on Equidistance Cylindrical Projection, the equation calculating rhumb line was established and the curvature of rhumb line was also analyzed. Then,the formula of drawing curves by straight lines describing general curves was deduced. Finally a kind of rhumb line describing algorithm which meets the requirements of a given precision has been put forward. Some experiments have been done to validate the algorithm＇s validity.The experiments show that the algorithm is characterized by briefness and feasible realization, which means the algorithm may describe the rhumb line accurately within the mapping error range in chart compilation specification.
出处
《测绘科学技术学报》
CSCD
北大核心
2015年第5期535-538,544,共5页
Journal of Geomatics Science and Technology
关键词
等距离正圆柱投影
极地海区
等角航线
以直代曲
图上描绘
equidistance cylindrical projection
polar sea
rhumb line
drawing curves by straight lines
description on chart
