摘要
精密单点定位技术能够提供全球高精度定位结果,其主要技术瓶颈在于定位收敛时间长,载波相位模糊度固定技术是加快PPP收敛速度、改善定位精度的主要手段之一。模糊度固定的可靠性问题在PPP定位中尤为突出,因为模糊度浮点解质量取决于服务端产品质量、接收机噪声特性和观测环境等多种因素,所以高可靠PPP模糊度固定技术仍然充满巨大挑战。为了保障PPP定位的可靠性,本文将最优整数等变估计(best integer equivariant, BIE)引入PPP模糊度估计过程中。BIE法利用GNSS模糊度整数解加权融合以获得最优的浮点模糊度估计值,可有效降低模糊度错误固定风险,同时又利用了模糊度整数解信息来提升模糊度估值精度,从而提升PPP定位精度,缩短模糊度收敛时间。本文选取了105个全球分布的MGEX测站对BIE估计PPP模糊度的性能进行验证,试验结果表明,与模糊度固定解相比,采用BIE估计PPP模糊度能够进一步改善坐标三分量(东、北、垂向)定位性能,收敛时间分别减少了37%、28%与31%,收敛后定位精度分别提高了9%、8%和3%。此外,BIE估计PPP模糊度定位结果的毛刺和阶跃现象更少。
Precision point positioning(PPP)technology can provide global high-precision positioning results,but its main technical bottleneck lies in the long positioning convergence time.The carrier phase ambiguity fixing technology is one of the main means to speed up PPP convergence and improve positioning accuracy.The reliability of ambiguity fixing is particularly prominent in PPP positioning,because the quality of the ambiguity-float solutions depends on the quality of the server product,various factors such as the noise characteristics of the receiver and the observation environment,making high reliability PPP ambiguity fixing technology is still full of huge challenges.In order to ensure the reliability of PPP positioning,we introduce the best integer equivariant(BIE)estimator into the PPP ambiguity estimation process.The estimator improves the estimation accuracy of float ambiguities through multiple ambiguity-fixed solution weighting methods,thereby improving the PPP positioning accuracy and shortening the ambiguity convergence time.105 globally distributed MGEX stations are selected to verify the performance of BIE in PPP ambiguity estimation.Experimental results showed that compared with the ambiguity-fixed solutions,using BIE to estimate PPP ambiguities can further improve the positioning performance of east,north and up components of the coordinates,the convergence time of which can be shortened by 37%,28%and 31%,and the positioning accuracy of which is improved by 9%,8%and 3%,respectively.Furthermore,there are fewer glitches and steps in the positioning results derived from BIE-based PPP.
作者
周锋
杨宇泽
王磊
徐天河
ZHOU Feng;YANG Yuze;WANG Lei;XU Tianhe(College of Geodesy and Geomatics,Shandong University of Science and Technology,Qingdao 266590,China;State Key Laboratory of Geodesy and Earth's Dynamics,Innovation Academy for Precision Measurement Science and Technology,Chinese Academy of Sciences,Wuhan 430077,China;State Key Laboratory of Information Engineering in Surveying,Mapping,and Remote Sensing,Wuhan University,Wuhan 430079,China;Institute of Space Science,Shandong University,Weihai 264209,China)
出处
《测绘学报》
EI
CSCD
北大核心
2022年第8期1779-1786,共8页
Acta Geodaetica et Cartographica Sinica
基金
国家自然科学基金(41904027
41904011
42074036)
中国博士后科学基金(2020M673669)
大地测量与地球动力学国家重点实验室开放研究基金(SKLGED2020-3-2-E)
山东省自然科学基金(ZR2019QD003)。
关键词
精密单点定位
最优整数等变
模糊度估计
定位性能
precise point positioning
best integer equivariant
ambiguity estimation
positioning performance
