Today’s society is highly reliant on time and frequency synchronization, e.g., in communications systems and financial networks. Precise timing is more and more derived from satellite navigation receivers that are unfortunately very susceptible to various signal threats. We studied the performance of global navigation satellite system (GNSS) timing under different operating conditions and tested the effectiveness of different techniques that improve timing receiver robustness. These features were tested under various threat scenarios related to specific vulnerabilities in GNSS-based timing, such as interference and navigation message errors, and their efficiency was analyzed against the corresponding scenarios. We found that interference or meaconing-type spoofing can threaten GNSS timing, but it can be detected by means of automatic gain control (AGC) and carrier-to-noise ratio-based methods. GNSS interruptions due to interference can be bridged by a local oscillator holdover technique based on a Kalman filter whose parameters are based on a GNSS time solution. Navigation message errors are mitigated by the European Geostationary Navigation Overlay Service (EGNOS), and constellation-wide timing errors can be detected by the use of a dual-constellation [global positioning system (GPS)-Galileo] cross-check. Dual-frequency operation for timing, in addition to mitigating first-order ionospheric effects, was found to be more robust to interference with the option to fall back to single frequency.

中文翻译：

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基于 EGNSS 的计时在各种威胁条件下的性能

当今社会高度依赖时间和频率同步，例如在通信系统和金融网络中。精确授时越来越多地来自卫星导航接收器，不幸的是，卫星导航接收器非常容易受到各种信号威胁的影响。我们研究了全球导航卫星系统 (GNSS) 授时在不同操作条件下的性能，并测试了提高授时接收机稳健性的不同技术的有效性。这些功能在与基于 GNSS 授时中的特定漏洞相关的各种威胁场景下进行了测试，例如干扰和导航消息错误，并针对相应场景分析了它们的效率。我们发现干扰或干扰型欺骗会威胁到 GNSS 计时，但它可以通过自动增益控制 (AGC) 和基于载噪比的方法进行检测。由于干扰导致的 GNSS 中断可以通过基于卡尔曼滤波器的本地振荡器保持技术进行桥接，该滤波器的参数基于 GNSS 时间解。欧洲地球同步导航覆盖服务 (EGNOS) 可以减轻导航消息错误，并且可以通过使用双星座 [全球定位系统 (GPS)-伽利略] 交叉检查来检测星座范围的计时错误。除了减轻一阶电离层效应外，还发现用于计时的双频操作对回退到单频选项的干扰更为稳健。由于干扰导致的 GNSS 中断可以通过基于卡尔曼滤波器的本地振荡器保持技术进行桥接，该滤波器的参数基于 GNSS 时间解。欧洲地球同步导航覆盖服务 (EGNOS) 可以减轻导航消息错误，并且可以通过使用双星座 [全球定位系统 (GPS)-伽利略] 交叉检查来检测星座范围的计时错误。除了减轻一阶电离层效应外，还发现用于计时的双频操作对回退到单频选项的干扰更为稳健。由于干扰导致的 GNSS 中断可以通过基于卡尔曼滤波器的本地振荡器保持技术进行桥接，该滤波器的参数基于 GNSS 时间解。欧洲地球同步导航覆盖服务 (EGNOS) 可以减轻导航消息错误，并且可以通过使用双星座 [全球定位系统 (GPS)-伽利略] 交叉检查来检测星座范围的计时错误。除了减轻一阶电离层效应外，还发现用于计时的双频操作对回退到单频选项的干扰更为稳健。可以通过使用双星座 [全球定位系统 (GPS)-伽利略] 交叉检查来检测星座范围的定时错误。除了减轻一阶电离层效应外，还发现用于计时的双频操作对回退到单频选项的干扰更为稳健。可以通过使用双星座 [全球定位系统 (GPS)-伽利略] 交叉检查来检测星座范围的定时错误。除了减轻一阶电离层效应外，还发现用于计时的双频操作对回退到单频选项的干扰更为稳健。