GPS/Galileo组合导航的模糊度搜索空间

为了组合导航的载波相位模糊度固定，将目前在GPS中常用的模糊度固定方法--最小二乘降相关平差（LAMBDA）法直接应用于GPS/Galileo组合模糊度固定，发现其搜索空间的确定方法并不能很好地适应GPS/Galileo组合中模糊度维数较高的情况。通过对常规LAMBDA搜索空间确定方法的分析比较，在传统方法的基础上提出了一种专门针对高维模糊度固定的搜索空间确定方法--修正法确定模糊度搜索空间。通过对修正法进行仿真试验，证明该方法能保证在GPS/Galileo组合定位模式下实际备选模糊度个数基本与预先设定的备选模糊度个数一致，进而能在不降低模糊度固定成功率的基础上有效提高LAMBDA模糊度固定的搜索效率，其性能优于传统的模糊度搜索空间确定方法。

Determination of the Ambiguity Search Space in Hybrid GPS/Galileo Navigation

In order to fix the ambiguities in hybrid GPS/Galileo navigation and positioning, several conventional space determining methods for least squares ambiguity decorrelation adjustment (LAMBDA) in GPS scenario were adopted in GPS/Galileo hybrid scenario. Simulation results show the conventional space-determining methods can′t meet the performance requirements for the high dimension in ambiguity vector. Compared to the conventional methods in determining LAMBDA ambiguity-search space, a new space-determining method specifically for high-dimension ambiguity vector was proposed. The simulation tests indicated that the proposed algorithm guaranteed an essential alignment of real and predefined candidate ambiguity numbers in joint positioning mode, and hence improved the searching efficiency without scarifying success ratio in determining the phase ambiguity.