变基线约束的GNSS单频单历元姿态测量新算法

New algorithm for single-frequency single-epoch attitude determination with dynamic baseline constraint

针对基于值域的GNSS姿态测量算法没有考虑工程应用中基线小动态变化的问题,推导了模糊度反约束值域搜索算法的搜索误差模型,研究了该误差模型对算法成功率的影响,分析了利用基线残差最小固定模糊度在工程应用中的不可靠性,提出了变基线约束的单频单历元姿态测量新算法:以基线长度小动态变化为约束,以惯性导航设备(INS)提供的粗略方位角、俯仰角为辅助,通过对基线长度、俯仰角、方位角三维搜索确定模糊度搜索域,以基于模糊度残余最小的无参化目标函数固定模糊度。试验结果表明,新算法能够在基线动态变化±10 cm、方位角偏差±5°、俯仰角偏差±5°情况下,实现模糊度的单频单历元固定和载体高精度姿态测量,并具有较高的成功率。

In view that the range-based GNSS attitude measurement algorithm does not consider the small dynamic change of baseline in the engineering application, the new algorithm is proposed by analyzing the value-domain search algorithm with ambiguity inverse constraint. Based on the GNSS attitude determination whose result zone was bounded by ambiguity, the error model in determining search zone is derived, the error model＇s effect on success rate of determining search zone is analyzed, and the unreliability of the objective function based on minimization of the baseline length residual is studied. Constrained by the range of baseline length and assisted by an INS, the new algorithm determine the search zone by searching the length, pitch angel and course angel, and then fix the integer ambiguity with the no-parameter objective function based on the minimization of ambiguity residual. Experiment results show that the new algorithm can fix the integer ambiguity in single epoch and single frequency with high successful rate in the situation that the range of baseline length change is ±10 cm, the constrain of pitch angel is ±5°, and the constrain of course angel is ±5°.