基于凸包Graham扫描法的多系统融合精密单点定位快速选星算法

摘要

鉴于传统选星算法不能快速获得理想的卫星空间构型,在讨论定位精度计算模型、多系统融合GDOP值影响因素和分析基于凸包Graham扫描的选星算法原理的基础上,编程实现了基于凸包Graham扫描法的多系统融合精密单点定位快速选星算法,并对该算法的选星效果及定位效率进行仿真实验.结果表明,该算法的选星数能够稳定在8～10颗,其星座GDOP得到明显优化,空间构型得到明显改善;与传统方法相比,X、Y、H方向收敛时间的优化率分别达到40％、20％和7％,且定位精度更高,对于促进模糊度快速固定和改善定位效率有重要意义.%The convergence speed and the precision of integrated multi satellite systems have a great relationship with the number and the space configuration of visible satellites and efficiency of system algorithm.The traditional selection algorithm cannot rapidly obtain the ideal spatial configuration,so,in this paper,the influence factors of the positioning accuracy calculation model and the GDOP value of integrated multi systems are discussed.An algorithm of convex hull with Graham's scan is analyzed and then a fast satellite selection algorithm based on convex hull with Graham's scan for multi satellite systems is achieved by programming.Meanwhile,simulation experiments are carried out on the selection effect and positioning efficiency of the proposed algorithm.Experimental results show that the number of selected satellites in this algorithm can be stabilized at 8 to 10,the constellation GDOP is obviously optimized and the spatial configuration is obviously improved.The optimization rate of convergence time reaches 40％,20％ and 7％ corresponding respectively to X,Y,H with the traditional algorithm,and the positioning accuracy is higher.These results hold important significance in quick repair of ambiguity and improving positioning efficiency.