A new tightly coupled method for high-rate seismogeodesy: a shake table experiment and application to the 2016 M-w 6.6 central Italy earthquake
A new tightly coupled method for high-rate seismogeodesy: a shake table experiment and application to the 2016 M-w 6.6 central Italy earthquake
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一种新的高速地震测量紧耦合方法：振动台实验及其在 2016 年意大利中部 M-w 6.6 地震中的应用
DOI：
10.1093/gji/ggab313
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发表时间：
2021
影响因子：
2.8
通讯作者：
Liu Jingnan
中科院分区：
文献类型：
--
作者：
Fang Rongxin;Zheng Jiawei;Shu Yuanming;Lv Huanghui;Shi Chuang;Liu Jingnan
高速率全球导航卫星系统（GNSS）已成为一种有效的地震波形恢复方法，但与地震仪器相比，它具有采样率相对较低和噪声水平较高的局限性。在这项研究中，我们提出了一种新的地震大地测量方法，通过集成GNSS和加速度计数据，以获得最佳的实时地震波形。与传统的基于GNSS相对定位或精密单点定位的积分方法不同，新方法采用GNSS时差技术，继承了其在实时、高精度速度解算方面的独特优势。此外，通过结合紧耦合结构，它可以克服级联问题，并提供更准确和鲁棒的波形相比，其松散耦合的对应。通过一组振动台实验，将该方法的性能与传统的松耦合方法在具有挑战性的环境中进行了比较。如果使用三颗全球导航卫星系统卫星，这种方法可以将速度和位移的准确度分别提高42%和87%。如果有四颗或更多的全球导航卫星系统卫星，该方法的速度和位移平均改进分别达到25%和41%。然后，我们通过模拟振动台实验和2016年意大利中部Mw6.6地震期间的GNSS和加速度计数据并置来验证该方法的全部性能。仿真和实际分析表明，新的集成方法可以充分利用GNSS和加速度计传感器的互补特性。该方法能实时或近实时地提供更精确的宽频带速度和位移波形，在地震预警和快速震源反演中具有很好的应用前景。
High-rate global navigation satellite system (GNSS) has emerged as an effective method to recover seismic waveforms without saturation and drifts, but it has the limitation of relatively lower sampling rate and higher noise level compared to seismic instruments. In this study, we present a new seismogeodetic method by integrating GNSS and accelerometer data to obtain optimal real-time seismic waveforms. Unlike traditional integration methods based on GNSS techniques of relative positioning or precise point positioning, the new method uses a GNSS time difference technique and inherits its unique advantage in real-time and high-accuracy velocity solutions. Furthermore, by incorporating the tightly coupled structure, it can overcome the cascading problem and provide more accurate and robust waveforms compared to its loosely coupled counterpart. The performance of this method is first compared with the traditional loosely coupled approach in challenging environments through a set of shake table experiments. With three GNSS satellites, this approach method can improve the accuracy of velocities and displacements by 42 and 87 per cent, respectively. With four or more GNSS satellites, the average improvements of the method reach 25 and 41 per cent for the velocities and displacements, respectively. We then validate the full performances of the method through simulated shake table experiments and collocated GNSS and accelerometer data during the 2016Mw6.6 central Italy earthquake. The simulated and real-event analyses demonstrate that the new integration method can take full advantage of the complementary characteristics of GNSS and accelerometer sensors. By providing more accurate and broad-band velocity and displacement waveforms in a real-time or near-real-time manner, this method is quite promising in earthquake early warning and rapid source inversion.