摘要
GNSS模糊度降相关通过整数变换优化条件方差的排列顺序,提高搜索效率。降相关和条件方差的关系及其评价是关键问题之一。针对这一问题,本文从理论上分析了排序后模糊度降相关与条件方差之间的数值关系,发现降相关性能与条件方差数值序列的平稳性有关,降相关性能越强,条件方差数值序列越平稳。基于这一理论关系,给出了“条件方差平稳度”定义,并将其作为评价降相关性能的指标。通过模拟和实测数据验证,并采用条件方差变化趋势图和搜索时间来定性和定量评价降相关性能,用以判定条件方差平稳度的合理性。试验结果表明,条件方差平稳度可以较精确直观地衡量模糊度的降相关性能。本文定义的指标揭示了模糊度降相关的本质。
GNSS ambiguity decorrelation is to optimize the permutation order of conditional variance by integer transformation,so as to improve the search efficiency.One of the key problems is how to evaluate the relationship between decorrelation and conditional variance.Aiming at this problem,this paper theoretically analyzes the numerical relationship between decorrelation and conditional variance after sorting.It is found that the decorrelation performance is related to the stationarity of the conditional variance sequence.The stronger the decorrelation performance,the more stable the conditional variance sequence.So based on this theoretical basis,the conditional variance stationarity is proposed as an index to evaluate the performance of decorrelation.The results are verified by both simulation and actual test experiments,and the conditional variance trend graph as well as search time are also used to qualitatively and quantitatively evaluate the performance of decorrelation,to determine the rationality of the conditional variance stationarity.The experimental results show that the conditional variance stationarity proposed in this paper can more accurately and intuitively measure the performance of ambiguity decorrelation.The index defined in this paper reveal the essence of GNSS ambiguity decorrelation.
作者
卢立果
刘万科
鲁铁定
马立烨
吴汤婷
杨元喜
LU Liguo;LIU Wanke;LU Tieding;MA Liye;WU Tangting;YANG Yuanxi(State Key Laboratory of Geo-Information Engineering, Xi’an Research Institute of Surveying and Mapping, Xi’an 710054, China;Faculty of Geomatics, East China University of Technology, Nanchang 330013, China;School of Geodesy and Geomatics, Wuhan University, Wuhan 430079, China;GNSS Research Center, Wuhan University, Wuhan 430079, China)
出处
《测绘学报》
EI
CSCD
北大核心
2020年第8期955-964,共10页
Acta Geodaetica et Cartographica Sinica
基金
国家自然科学基金(41804020,41774031)
国家重点研发计划(2016YFB0501405)
江西省自然科学基金(20202BAB212010,20192BAB217011)。
关键词
GNSS
模糊度
降相关
条件方差
评价指标
GNSS
ambiguity
decorrelation
conditional variance
evaluation index
