海洋测绘中船体姿态改正的误差分析

Error Analysis of the Attitude Correction in the Marine Surveying

船体姿态变化是海洋测绘中重要的误差来源,需要进行修正。姿态改正实际上是进行坐标系变换,存在着不同的坐标轴旋转顺序,对应的旋转矩阵形式也不一样。实际应用中发现不同的旋转矩阵导致不同的姿态改正结果,甚至出现错误的改正。仔细分析了姿态改正中的三种旋转方式,重点讨论了两种常用模型简化后的误差量级。研究后发现,坐标系变换中的旋转角并非姿态角,并由此导出了两种常用旋转方式对应的旋转角,它是纵摇角和横摇角的函数。采用正确的旋转角,不同的旋转方式能够得到一致的姿态改正结果。另外,在姿态改正精度要求不高于0.2m的前提下,第一种旋转方式可以采用简化模型。

The attitude correction plays an important role in the marine surveying. It is, in fact, the question of the coordinate transformation. In order to generate the transformed matrix, the three axes should be sequentially rotated. There are three different styles of axis rotation. If inappropriate rotation angles are used in those rotations, it will produce incorrect transformation results. In the paper, the errors, caused by rotation, are firstly discussed. Then, the formulae of rotation angles are derived for two popular cases in the ocean surveying. It is the function of pitch and roll angles. In the end, the errors are analyzed because of the formula simplification. The error, caused by the first case, is smaller than that of the second one. So the first simplification model is recommended in the application, if the required position is not accurate enough.