摘要
针对GPS-BDS系统偏差会导致GPS和BDS系统间的混合双差模糊度不具有整数特性,且其不完全稳定的问题,该文提出一种GPS/BDS系统偏差实时在线估计方法。通过将双差模糊度以单差模糊度之差的形式进行求解,然后再将以周为单位的单差模糊度投影为双差模糊度,以此消除GPS和BDS不同波长的影响;在此基础上,采用Kalman滤波对系统偏差进行实时动态估计。实验结果表明,该方法采用较少历元的观测数据便可使系统偏差收敛,并且收敛后十分稳定,可以将其作为校正参数;加入系统偏差改正的GPS/BDS紧组合定位在恶劣环境下表现良好,可将模糊度固定平均所需时间缩短29%,模糊度固定成功率提高45%。
GPS-BDS inter-system biases is the key factor resulting in the failure of GPS-BDS mixed double-differenced ambiguity fixing.The recent research showed that GPS-BDS inter-system biases is not completely stable,thus this paper proposed a real-time estimation algorithm for the GPS-BDS inter-system biases.In order to solve the problem of the different wavelengths between GPS and BDS,double-differenced ambiguities were estimated in the form of the difference between single-differenced ambiguities,then the single-differenced ambiguities were transformed to double-differenced ambiguities in the unit of cycle.Based on which,the inter-system biases was real-time estimated by Kalman filter.Experimental results showed that the velocity of convergence was quick for inter-system biases by this approach,and the parameter of inter-system biases was stable after convergence,which could be used as correction parameter;GPS-BDS tight combining with inter-system biases corrected performed well under poor observing condition,which could improve the mean time-to-ambiguity-fixing by 29%,and the success rate of ambiguity-fixing by 45%.
出处
《测绘科学》
CSCD
北大核心
2016年第12期106-109,115,共5页
Science of Surveying and Mapping
基金
国家重点研发计划项目(2016YFC0803102)
辽宁省教育厅创新团队项目(LT2015013)
国家自然科学基金项目(41501504)
大学生创新创业训练计划项目(201610147039
201610147078)
现代城市测绘国家测绘地理信息局重点实验室开放课题资助项目(20111203W)
