A single-receiver geometry-free approach to stochastic modeling of multi-frequency GNSS observables
A single-receiver geometry-free approach to stochastic modeling of multi-frequency GNSS observables
复制标题
多频率 GNSS 可观测值随机建模的单接收器无几何方法
DOI：
10.1007/s00190-020-01366-8
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发表时间：
2020-03
影响因子：
4.4
通讯作者：
Yuan Yunbin
中科院分区：
文献类型：
--
作者：
Zhang Baocheng;Hou Pengyu;Liu Teng;Yuan Yunbin
随机模型的合理选择对全球卫星导航系统（GNSS）数据处理具有重要意义。鉴于对随机建模的广泛研究主要基于采用零基线和/或短基线的相对（或微分）方法，本工作提出了一种绝对方法，该方法依赖于独立接收器，并通过将最小二乘方差分量估计应用于无几何函数模型，从而促进了多频GNSS观测值在无差别水平上的随机特性表征。在发展绝对方法时，通过在码观测方程中引入类似模糊的参数，特别注意了码的多径效应。采用相对和绝对两种方法，对中国北斗和欧洲伽利略两个新兴星座不同类型接收机在多个频率下采集的码相观测数据的精度、交叉和时间相关性进行了表征。我们的第一个发现是，就精度而言，绝对方法得到的数值与基于零基线的相对方法得到的数值几乎相同。然而，这两种方法给出了相互矛盾的结果，当使用相对（绝对）方法时，发现（不）发生在北斗相位观测值之间。我们对这种差异的解释是，在相对方法中发现的相互关联源于两个接收器共享的部件（天线，电缆，低噪声放大器），创建零基线。时间相关性只有在多径效应存在的情况下才有意义，比如基于短基线的相对方法；在绝对（或基于零基线的相对）方法中，这种相关性在很大程度上较弱（或理想情况下不存在）。此外，对于同一类型但受不同多径效应影响的两个接收机，采用绝对方法确定的随机特性几乎相同。我们认为这是绝对方法对多径效应具有鲁棒性的有力证据。因此，本文提出的绝对方法是相对方法的一个有希望的补充，似乎特别有利于基于无差观测值的GNSS定位、导航和授时技术，特别是精确点定位。
The proper choice of stochastic model is of great importance to global navigation satellite system (GNSS) data processing. Whereas extensive investigations into stochastic modeling are mainly based on the relative (or differential) method employing zero and/or short baselines, this work proposes an absolute method that relies upon a stand-alone receiver and works by applying the least-squares variance component estimation to the geometry-free functional model, thus facilitating the characterization of stochastic properties of multi-frequency GNSS observables at the undifferenced level. In developing the absolute method, special care has been taken of the code multipath effects by introducing ambiguity-like parameters to the code observation equations. By means of both the relative and absolute methods, we characterize the precision, cross and time correlation of the code and phase observables of two newly emerging constellations, namely the Chinese BDS and the European Galileo, collected by a variety of receivers of different types at multiple frequencies. Our first finding is that so far as the precision is concerned, the absolute method yields nearly the same numerical values as those derived by the zero-baseline-based relative method. However, the two methods give contradictory results with regard to the cross correlation, which is found (not) to occur between BDS phase observables when use has been made of the relative (absolute) method. Our explanation to this discrepancy is that the cross correlation found in the relative method originates from the parts (antenna, cable, low noise amplifier) shared by two receivers creating a zero baseline. The time correlation is only of significance when the multipath effects are present, as is the case with the short-baseline-based relative method; this correlation turns out to be largely weaker (or ideally absent) in the absolute (or zero-baseline-based relative) method. Moreover, with the absolute method, the stochastic properties determined for two receivers of the same type but subject to different multipath effects are virtually the same. We take this as a convincing evidence that the absolute method is robust against multipath effects. Hence, the absolute method proposed in the present work represents a promising complement to the relative method and appears to be particularly beneficial to GNSS positioning, navigation and timing technologies based on the undifferenced observables, typically the precise point positioning.
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DOI：
10.1007/bf02521994
发表时间：
1970-03
期刊：
Bulletin Géodésique (1946-1975)
影响因子：
--
作者：
K. Kubik
通讯作者：
K. Kubik
影响因子：
5
作者：
Kazmierski, Kamil;Hadas, Tomasz;Sosnica, Krzysztof
通讯作者：
Sosnica, Krzysztof
影响因子：
--
作者：
D. Laurichesse;F. Mercier;J. Berthias;P. Broca;L. Cerri
通讯作者：
D. Laurichesse;F. Mercier;J. Berthias;P. Broca;L. Cerri
影响因子：
2.6
作者：
Shaoshi Wu;Xiubin Zhao;Chunlei Pang;L. Zhang;Y. Wang
通讯作者：
Shaoshi Wu;Xiubin Zhao;Chunlei Pang;L. Zhang;Y. Wang
影响因子：
4
作者：
K. Koch
通讯作者：
K. Koch