建立了一种基于多天线GPS/SINS的全组合测姿模型; 在位置、速度组合的基础上，利用星站双差观测量实现姿态测量，并证明了PWCS定理可用于分析该类系统的可观测性。研究了系统在不同可见星数目情况下的状态可观测性，并通过一段仿真航迹，对比了模型的测姿精度等性能。结果表明，当可见星数目大于等于4颗时，系统状态即完全可观测，此时，导航系统滤波参数能够较快收敛，并且达到较高的测姿精度。而在此基础上继续增加可见星数目、增加姿态观测量并不能使系统的测姿精度和收敛速度得到明显改善。

measuring is achieved by double-difference observed quantities, which is based on “Position-Velocity Integrated System”. It is proved that PWCS theory is appropriate for this kind of system's observability analysis. Observability of the system under different N Asset Coverage is studied, and their ability of attitude measuring, sun as precision, is compared by simulation. The results show that, while the N Asset Coverage is more than 4, the system become completely observable. In such cases, the filtering parameter of navigation system can get convergent rapidly with a good precision. While continued increasing the N Asset Coverage and observed quantities of attitude measuring on this basis, the precision and convergence rate will not improve accordingly.