GNSS-A直线测量模式及航迹组合优化分析

海底控制点的GNSS-A定位精度受到测量船相对于海底控制点的航迹影响，本文针对圆形测量模式垂向几何结构较弱的问题，给出了一种新的基于嵌套圆的直线测量模式的分析方法，研究了直线测量模式的参数可估性，并给出了直线测量模式得到唯一解的条件.同时，详细分析了圆形测量模式下要增加十字航迹的原因，推导出圆加十字测量模式下获得海底控制点最优三维点位精度的走航半径约为1.15倍水深.理论分析表明，在圆形测量模式下增加直线航迹能够有效增强其几何结构，提升定位效能.此外，针对是否存在唯一的最优航迹进行了思考，并给出了相应的见解.最后，利用深海实测数据验证了理论推导的结果，圆加十字测量模式较圆形测量模式对海底控制点定位的精度提升可达1.4 cm.

GNSS-A straight-line survey pattern and trajectory combination optimization analysis

The GNSS-A positioning accuracy of seafloor control point is influenced by the trajectory of the surveying vessel. Targeted at solving the problem of the weak vertical components geometry structure in circular measurement pattern, the paper has proposed a new analytical method of liner measurement pattern based on nested circles, studied the parameter estimability of liner measurement pattern, and given the conditions for obtaining a unique solution in the linear measurement pattern. Meanwhile, the paper has analyzed in detail the reason for adding cross-track in the circular measurement mode, and concluded that the sailing radius of the optimal 3D accuracy of the seafloor control point in the circular measurement pattern and cross-track measurement pattern is 1.15 times the water depth. It has also pointed out that adding a straight-line trajectory in circular measurement pattern can effectively enhance the geometry structure and improve the positioning efficiency. Furthermore, it has put forward some thoughts and opinions on whether there is a unique optimal trajectory. Finally, the theoretical results are verified with the measured data of deep sea. That is, compared with the circular measurement pattern for the positioning of seafloor control points, the accuracy of the circular and cross-track measurement pattern can be improved by 1.4 centimeters.