基于改进蚁群算法的区域伪卫星增强GPS星座优化设计

Optimal design of regional pseudolite-augmented GPS constellation based on improved ant colony algorithm

为实现信号遮挡严重区域伪卫星增强GPS系统的最优导航定位性能,提出了增强星座优化模型及基于改进蚁群算法的实现方法.首先,根据恶劣定位环境可见GPS卫星时空分布不均的特点,基于精度、可用性、连续性等导航性能指标以及系统投入成本和工程地质、地形条件建立增强星座的优化模型.然后,针对该模型主要评价指标的特点,利用改进的蚁群算法实现伪卫星最优位置的搜索.结合具有典型峡谷特征的小湾电站2号山梁相关实验,从多角度给出建立优化模型的准则及其对搜索算法的影响.实验结果表明,经优化设计后该区域的导航定位性能提高了35%～70%,能够满足形变监测系统的设计要求.

In order to obtain the optimum navigation and positioning performance under some unfavorable surveying conditions,a pseudolites（PL）-augmented global positioning system（GPS） constellation optimization model and the realization method based on improved ant colony algorithm are proposed.Since the distribution of observable GPS satellites is mostly irregular on space and time under such environments,the PL-augmented constellation optimum model is established based on accuracy,availability and continuity with consideration for the cost and the condition of topography and geology.According to the features of the model,the improved ant colony algorithm is developed for searching the optimum location of PL.No.2 steep slope of Xiaowan Hydropower Station is selected as the field test site.With these experiments,the strategies for building the optimal model and its influence on the searching method are discussed from various aspects.The results indicate that the navigation performance can be increased by 35% to 70% after constellation optimal design and the PL-augmented GPS system can meet the requirements for the deformation monitoring system.