GPS Multipath Analysis Using Fresnel Zones
GPS Multipath Analysis Using Fresnel Zones
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DOI：
10.3390/s19010025
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发表时间：
2019-01-01
期刊：
影响因子：
3.9
通讯作者：
Kuhlmann, Heiner
中科院分区：
文献类型：
--
作者：
Zimmermann, Florian;Schmitz, Berit;Kuhlmann, Heiner
GNSS（全球导航卫星系统）多径效应已经进行了数十年的科学研究，尽管已经开发了许多方法和技术来减轻这种影响，但它仍然是许多GNSS应用中的精度限制因素之一。由于多径是高度依赖于单个天线环境，仍然需要新的方法和进一步的调查，以增加这种系统的影响的理解。在本文中，菲涅尔区的概念被应用到两个不同方面的多径。首先，确定了卫星和接收机之间视线传输的菲涅尔区。通过将菲涅耳区的边界与障碍物自适应仰角掩模进行比较，可以识别潜在衍射信号并将其从位置估计过程中排除。所提出的方法可以提高具有固定模糊度的历元的百分比和定位精度。其次，菲涅耳区被用来分析由水平和空间有限的反射器引起的多径。模拟和真实的信号噪声（SNR）观测的比较揭示了菲涅尔区和反射器的重叠的百分比和多径的发生之间的关系。据发现，50%的重叠是足以引起多径效应。这是特别感兴趣的，因为这并不证实多径理论的理论假设。
GNSS (Global Navigation Satellite Systems) multipath has been subject to scientific research for decades and although numerous methods and techniques have already been developed to mitigate this effect, it is still one of the accuracy-limiting factors in many GNSS applications. Since multipath is highly dependent on the individual antenna environment, there is still a need for new methods and further investigations to increase the understanding of this systematic effect. In this paper, the concept of Fresnel zones is applied to two different aspects of multipath. First, Fresnel zones are determined for the line-of-sight transmission between satellite and receiver. By comparing the boundary of the Fresnel zones to an obstruction adaptive elevation mask, potentially diffracted signals can be identified and excluded from the position estimation process. Both the percentage of epochs with fixed ambiguities and the positioning accuracy can be increased by the proposed method. Second, Fresnel zones are used to analyze the multipath induced by a horizontal and spatially-limited reflector. The comparison of simulated and real signal-to-noise (SNR) observations reveals a relationship between the percentage of the overlap of the Fresnel zone and reflector and the occurrence of multipath. It is found that an overlap of 50% is sufficient to induce multipath effects. This is of special interest, since this does not confirm theoretical assumptions of the multipath theory.