大圆距离及大圆航向的计算

在飞机选型中对各机型进行性能分析、经济性评估或编制飞行计划软件时,常需要根据航段两端点的经纬度坐标计算该航段的大圆距离及航向,在沿大圆航线飞行时也需要知道航路上各点的真航向及磁航向。本文用矢量方法导出了根据起止点的经纬度坐标计算该航段大圆距离及大圆航向的公式以及沿大圆航线飞行时根据给定点的经度计算其纬度和真航向的公式,并且用算例做了验证,结果表明这些公式是正确的。

Calculation of the Great-circle Distance and Heading

While analysing the performance,estimating the economic results or programming the flight plans,of different types of aircraft in aircraft-type selection,the calculations of the great-circle distance and heading of a segment by the longitude and latitude of its terminals are often needed.In addition,in flying along a greatcircle route,the true and magnetic headings of each point on the route are also to be found.In this paper,new formulas have been derived and verified by the vector algorithm and an algorithmic example respectively.They are used to calculate the great-circle distance and heading of a segment by the longitude and latitude of both terminals,and to calculate the latitude and the true heading by the position of a given point on a great-carcle route.