GPS/BDS粒子群优化算法紧组合定位方法及精度分析

An algorithm and results analysis for GPS/BDS tightly coupled combination based on particle swarm optimization

全球卫星导航系统紧组合定位中,系统间偏差(inter-system bias,ISB)需要多历元后处理的估计方式,并与接收机重启等因素有关。针对该问题,文章将求解ISB参数问题转化为求解系统间小数偏差(fractional inter-system bias,F-ISB)参数问题,利用粒子群优化(particle swarm optimization,PSO)算法单历元实时估计F-ISB与坐标参数,在此基础上分析了收星受限情况下模糊度固定成功率和定位精度。实验结果表明,不同品牌接收机的全球定位系统(Global Positioning System,GPS)与北斗卫星导航系统(BeiDou Navigation Satellite System,BDS)的F-ISB在一定时间内具有时域稳定性,F-ISB在不同截止高度角下实时单历元估计偏差均小于0.1周;实时F-ISB改正的紧组合模型在截止高度角为40°的收星受限情况下,单历元定位精度与松组合模型一致,模糊度固定成功率由74.2%提升到90.65%。

When the global navigation satellite system is combined,the hardware delays at the receiver need to be estimated in advance and are related with the restarting of the receiver.Aiming at the problem,this paper transforms the solution of inter-system bias(ISB)parameter into the solution of fractional inter-system bias(F-ISB)parameter and uses particle swarm optimization(PSO)to estimate the F-ISB and coordinate parameters in single-epoch.On this basis,the success rate of ambiguity fixation and positioning accuracy under limited satellites are analyzed.Experiments show that the F-ISBs of Global Positioning System(GPS)/BeiDou Navigation Satellite System(BDS)of receivers of different brands have time-domain stability within a certain period of time and the real-time single-epoch calculation deviation of F-ISB at different cut-off angles is less than 0.1 week.The tightly coupled model of real-time F-ISB correction algorithm has same positioning accuracy with the loosely coupled model under the cut-off angle of 40°,and the ambiguity resolution rate is increased from 74.2%to 90.65%.