Further observations of GPS satellite oscillator anomalies mimicking ionospheric phase scintillation
Further observations of GPS satellite oscillator anomalies mimicking ionospheric phase scintillation
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DOI：
10.1007/s10291-013-0338-4
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发表时间：
2014-07-01
期刊：
影响因子：
4.9
通讯作者：
Mitchell, Cathryn N.
中科院分区：
文献类型：
--
作者：
Benton, Christopher J.;Mitchell, Cathryn N.
以前曾报告过一个事件，其中Navstar 43全球定位系统卫星的信号包含相位异常，以模仿电离层闪烁。我们已经观察到来自同一颗卫星的另外25个事件，加上来自另外三颗卫星的事件。我们的数据包括来自不同制造商的宽距离接收器（相距达6，590公里）的同时观测，进一步排除了局部效应的可能性。其中两个事件涉及一颗卫星（GPS IIF SV-2）广播L2 C信号。该信号包含与L1信号相匹配的相位偏差，但具有120/154的乘法因子。这排除了真正的电离层闪烁事件的可能性，因为它与等离子体色散关系不匹配。然而，它确实同意从卫星振荡器的异常中可以预期的情况。虽然先前报告的事件可能被视为反常事件而不予考虑，但现在很明显，这些事件是一种持续存在的现象。它们有可能用错误的数据破坏地球物理研究，并在系统中产生错误的警报，以预先警告由于闪烁导致的GPS中断。
An incident has previously been reported where the signal from the Navstar 43 Global Positioning System (GPS) satellite contained phase anomalies in such a way as to mimic ionospheric scintillation. We have observed another 25 events from the same satellite, plus events from three more satellites. Our data includes simultaneous observations from widely spaced receivers (up to 6,590 km apart), from different manufacturers, further ruling out the possibility of local effects. Two of the events involved a satellite (GPS IIF SV-2) broadcasting the L2C signal. This signal contained phase deviations matching those of the L1 signal, but with a 120/154 multiplicative factor. This rules out the possibility of a genuine ionospheric scintillation event, as it does not match the plasma dispersion relation. It does, however, agree with what can be expected from an anomaly in the satellite's oscillator. While the previously reported event could be dismissed as a freak occurrence, it is now apparent that these events are a persistent phenomenon. They have the potential to corrupt geophysical research with false data and to generate false alarms in systems to forewarn of GPS outages due to scintillation.