常用极区海图投影直接变换的闭合公式

Closed Formulae of Direct Transformations Between Commonly Used Polar Chart Projections

针对新形势下北极航行对海图保障的迫切需求,研究了常用极区海图投影的直接变换问题。视地球为球体,引入余纬度,给出了极球面投影、横墨卡托投影和日晷投影等常用极区海图投影的正反解公式,在此基础上,系统地推导出了三种投影中任意两种投影间的直接变换公式。该公式为形式简单的闭合公式,可供极区海图投影变换和航海导航参数计算使用。

Aimed at the new situation of the urgent need of nautical charts to ensure Arctic voyages,the direct transformations between commonly used polar chart projections are studied.The forward and reverse formulae of polar stereographic,transverse Mercator and gnomonic projections are given considering the earth as a sphere by the introduction of colatitude.Based on these,the formulae of direct transformations between the commonly used polar chart projections are systematically derived.These formulae have concise and closed form,and could be used for transformations between polar chart projections and navigation parameter calculation.