UC Berkeley, Seismological Laboratory, Berkeley, California, USA.
Sci Rep. 2011;1:44. doi: 10.1038/srep00044. Epub 2011 Jul 22.
Recently, co-seismic seismic source characterization based on GPS measurements has been completed in near- and far-field with remarkable results. However, the accuracy of the ground displacement measurement inferred from GPS phase residuals is still depending of the distribution of satellites in the sky. We test here a method, based on the double difference (DD) computations of Line of Sight (LOS), that allows detecting 3D co-seismic ground shaking. The DD method is a quasi-analytically free of most of intrinsic errors affecting GPS measurements. The seismic waves presented in this study produced DD amplitudes 4 and 7 times stronger than the background noise. The method is benchmarked using the GEONET GPS stations recording the Hokkaido Earthquake (2003 September 25th, Mw = 8.3).
最近，利用 GPS 测量完成了近场和远场的同震震源特征描述，取得了显著成果。然而，从 GPS 相位残差推断出的地面位移测量的精度仍然取决于天空中卫星的分布。我们在这里测试了一种基于视线路径（LOS）的双差（DD）计算的方法，该方法可以检测到三维同震地面运动。DD 方法在很大程度上不受影响 GPS 测量的大多数固有误差的影响，是一种准解析方法。本研究中提出的地震波产生的 DD 幅度比背景噪声强 4 到 7 倍。该方法使用记录北海道地震（2003 年 9 月 25 日，Mw=8.3）的 GEONET GPS 站进行了基准测试。
