空间飞行体地心坐标与大地坐标的快速精确转换

Strict and Speedy Transformation From Geocentric Coordinates to Geodetic Coordinates for the Spacecraft

在空间任一点的子午面内 ,建立该点到地球子午椭圆的法线方程 ,以法线与子午椭圆交点的地心坐标为参数 ,导出大地高程和大地纬度的近似算法和严密算法。近似算法十分简单 ,使用有三角函数的手持计算器就可以完成计算。对于高度低于 360 0 0km的任何空间点 ,大地高h和大地纬度B的精度分别优于 31m和 0 1 7°。以近似算法的中间结果为初值 ,可将大地坐标的解算转化为一个二元一次方程组 ,解算非常简单 ,用PC在瞬间即可完成一批空间点的计算并可获得与真值完全相同的大地坐标 ,这为空间飞行体坐标的实时快速计算 。

Within the meridian plane at any point in the space, the normal equation from the point to the Earth's meridian ellipsoid is established. With the geocentric coordinate at the intersection point of the normal and the meridian ellipsoid as the parameters for calculation, the approximate algorithm and strict algorithm for the geodetic height and geodetic latitude are derived. The approximate algorithm is very simple, which can be accomplished by a hand calculator with the trigonometric function. For any point with the height lower than 36000km, the accuracy of h and B can be better than 31m and 0 17° respectively. Taking the intermediate result by the approximate algorithm as the initial value, the calculation of geodetic coordinates can be transformed into a binary first-order equation that can be solved simply. If PC is used, the calculation of a number of spatial points can be accomplished in a moment and the geodetic coordinates that are the same as the true values can be obtained, which provided a support of new technology for the real-time speedy coordinate calculation for the spacecraft.