中文摘要：

为解决目前贝塞尔大地主题正解算法中存在的问题，应用球面三角形正余弦定理和三角级数回求方法，给出一种适用于任意条件的大地主题正解的改进算法．该算法不需要迭代计算，适用传统正解算法中的奇异情况，解决了求解三角方程中方位角的多值对应问题．仿真结果表明，该算法与距离长短无关，适用于任意特殊情形，具有通用性，对远洋大地线航法计算具有一定的应用价值．

英文摘要：

This paper presented an improved arithmetic for direct solution of geodetic problem in all conditions to cope with Bessel＇s direct geodetic problems. Sine and cosine theory and the reverse solution of trigonometric series were applied. Simulation results show that the improved algorithm has nothing to do with the distance, and is suitable for the arbitrarily special situations without iterative calculations. The azimuth multiple-valued corresponding problem in the solution of trigonometric equation was solved The improved algorithm can be applied in the area of ocean geodetic line sailing computation.