High-rate precise point positioning (PPP) to measure seismic wave motions: an experimental comparison of GPS PPP with inertial measurement units
High-rate precise point positioning (PPP) to measure seismic wave motions: an experimental comparison of GPS PPP with inertial measurement units
复制标题
用于测量地震波运动的高速精密单点定位（PPP）：GPS PPP 与惯性测量单元的实验比较
DOI：
10.1007/s00190-012-0606-z
复制
发表时间：
2013-04-01
影响因子：
4.4
通讯作者：
Yanagidani, Takashi
中科院分区：
文献类型：
--
作者：
Xu, Peiliang;Shi, Chuang;Yanagidani, Takashi
高速率GPS已被广泛用于构造位移波形和反演震源参数。国内外对高速率GPS精度的评估工作，几乎都是基于GPS相对定位的。我们建立了一个实验平台，外部评估50 Hz PPP位移波形的精度。由于振动台允许六个自由度中的任何一个运动，我们安装了一个惯性测量单元（IMU）来测量平台的姿态，并将IMU位移转换到GPS坐标系中。实验结果表明，高速率PPP可以在短时间内产生精度为2-4 mm的绝对水平位移波形和精度为亚厘米级的绝对垂直位移波形。实验结果表明，高速率PPP技术不需要固定的基准站，能够以与GPS相对定位技术同样高的精度检测绝对地震位移波形。我们还发现了一个小的缩放误差的IMU和一个小的时间偏移的高速率PPP和IMU位移波形之间的错位通过比较的幅度和互相关的位移波形。
High-rate GPS has been widely used to construct displacement waveforms and to invert for source parameters of earthquakes. Almost all works on internal and external evaluation of high-rate GPS accuracy are based on GPS relative positioning. We build an experimental platform to externally evaluate the accuracy of 50-Hz PPP displacement waveforms. Since the shake table allows motion in any of six degrees of freedom, we install an inertial measurement unit (IMU) to measure the attitude of the platform and transform the IMU displacements into the GPS coordinate system. The experimental results have shown that high-rate PPP can produce absolute horizontal displacement waveforms at the accuracy of 2–4 mm and absolute vertical displacement waveforms at the sub-centimeter level of accuracy within a short period of time. The significance of the experiments indicates that high-rate PPP is capable of detecting absolute seismic displacement waveforms at the same high accuracy as GPS relative positioning techniques, but requires no fixed datum station. We have also found a small scaling error of IMU and a small time offset of misalignment between high-rate PPP and IMU displacement waveforms by comparing the amplitudes of and cross-correlating both the displacement waveforms.