中文摘要：

整周模糊度固定是GNSS高精度动态定位的关键问题,为研究GPS/BDS（北斗卫星导航系统）组合定位对短基线模糊度搜索效率和固定成功率的提高效果,利用基于模糊度方差-协方差阵特征值平方根的模糊度搜索空间对比方法分别对短基线条件下GPS单系统、BDS单系统和GPS/BDS组合系统下的模糊度搜索空间进行对比分析。实验数据表明：GPS/BDS组合定位对各单系统的方差-协方差阵均有影响,从整体上可以缩小GPS和BDS单系统的模糊度搜索空间。最后对模糊度固定成功率进行了统计,结果表明,在单、双频条件下组合系统均可显著提高模糊度固定成功率和搜索效率。

英文摘要：

Ambiguity fixing is the key to GNSS high-precision dynamic positioning.In order to analyze the performance of a GPS/BDS combined system on ambiguity search efficiency and the success rate of ambiguity fixing on a short baseline,this paper proposes an ambiguity search region correlation method based on the square roots of the eigenvalues of the variance/covariance matrix of ambiguity.This method compares and analyzes the ambiguity search region in a single system GPS,a single system BDS and combined GPS/BDS system,respectively.Experimental results show that the GPS and BDS combination influences the variance/covariance matrix of each single system,and reduces the search region of each single system.Furthermore,the statistical results show that the combined GPS/BDS system can improve the success rate of ambiguity fixing and the ambiguity search efficiency significantly within single-and dual-frequency observations.