经纬仪交会测量时,常用方向余弦法计算目标坐标。因测角误差,各经纬仪指向目标的射线不相交,计算时有原理性误差。通过分析射线与目标的位置关系及光测设备的测量精度等,提出了用两条射线最短距离的加权值作为目标位置,优化了方向余弦法的计算模型。实测数据验证表明,优化后的方法提高了计算精度,是行之有效的。

In view of intersection measurement, direction cosine algorithm is often adopted to calculate coordinates. In fact, because of error of optical equipment, two light rays from them don't intersect at one point; the direction cosine method is inaccurate in principle. In this paper, through analysis of spatial relationship among rays, target, and measuring accuracy of optical measurement equipment, etc., the weighted value of the shortest distance was taken as the target coordinate. Tests show that the improved direction cosine method is effective, resulting in higher accuracy.