ETH Zurich, Institute of Geodesy and Photogrammetry, 8093 Zurich, Switzerland.
Sensors (Basel). 2018 Oct 31;18(11):3712. doi: 10.3390/s18113712.
By means of the time derivatives of Global Navigation Satellite System (GNSS) carrier-phase measurements, the instantaneous velocity of a stand-alone, single GNSS receiver can be estimated with a high precision of a few mm/s; it is feasible to even obtain the level of tenths of mm/s. Therefore, only data from the satellite navigation message are needed, thus discarding any data from a reference network. Combining this method with an efficient movement-detection algorithm opens some interesting applications for geohazard monitoring; an example is the detection of strong earthquakes. This capability is demonstrated for a case study of the 6.5 Mw earthquake of October 30, 2016, near the city of Norcia in Italy; in that region, there are densely deployed GNSS stations. It is shown that GNSS sensors can detect seismic compressional (P) waves, which are the first to arrive at a measurement station. These findings are substantiated by a comparison with data of strong-motion (SM) seismometers. Furthermore, it is shown that the GNSS-only hypocenter localization comes close (less than a kilometer) to the solutions provided by official seismic services. Finally, we conclude that this method can provide important contributions to a real-time geohazard early-warning system.
通过全球导航卫星系统（GNSS）载波相位测量的时间导数，可以高精度地估计独立单 GNSS 接收机的瞬时速度，达到几毫米/秒的水平；甚至可以达到十分之几毫米/秒的水平。因此，只需要卫星导航消息的数据，从而丢弃任何参考网络的数据。将这种方法与高效的运动检测算法相结合，为地质灾害监测开辟了一些有趣的应用；例如，检测强震。这项能力在 2016 年 10 月 30 日意大利诺尔恰市附近发生的 6.5 级地震的案例研究中得到了验证；在该地区，有密集部署的 GNSS 站。结果表明，GNSS 传感器可以检测到地震压缩波（P 波），这些波是第一个到达测量站的波。这些发现通过与强震（SM）地震仪的数据进行比较得到了证实。此外，结果表明，GNSS 仅的震源定位接近（不到一公里）官方地震服务提供的解决方案。最后，我们得出结论，该方法可以为实时地质灾害预警系统提供重要贡献。
