高频GPS坐标时序的噪声特性分析

Noise Characteristics Analysis of the High-rate GPS Coordinate Time Series

为研究高频GPS坐标时序的噪声特性,对芦山地震前后三天,北京时间8:00—9:00,位于四川盆地8个CORS站50Hz的高频观测资料进行解算与分析。分析过程中,分别采用恒星日滤波和主成分滤波分析以及去除时空噪声,并采用功率谱分析经滤波后的坐标时序。结果表明,高频GPS坐标时序的谱指数在1.6~2.0间,符合白噪声+随机游走噪声模型特性。建议当利用高频GPS研究地表运动特性、监测大型建筑的运动结构或确定GPS动态实验平台姿态时,应考虑高频GPS坐标时序的这一噪声特性。

To investigate the noise characteristics of the highrate GPS coordinate time series,onehour highrate observations of eight CORS sites in the Sichuan basin from8:00-9:00Beijing time for three days,including the Lushan earthquake,are resolved and analyzed.The sidereal filtering and principle component analysis filtering are utilized to analyze and reduce the temporal and spatial noise separately;the power spectrum method is used to estimate the spectrum index.With the spectrum index from1.6to2,we consider the highrate coordinate time series are adjusted for white noise plus random walk noise characteristics.These results have important implications for the design of continuous GPS networks for crustal deformation and structural monitoring,and also for positioning and attitude determination of dynamic platforms.